Samuel Eto'o's hat-trick saw Chelsea to a 3-1 win over Manchester United at Stamford Bridge on Sunday that piled the pressure on the Premier League champions.
Victory left Jose Mourinho's Chelsea within two points of leaders Arsenal but this result meant title-holders United are 14 points adrift of the Gunners with 16 league games of the season remaining.
United's seventh league loss this term also turned the spotlight back on David Moyes, the successor chosen by Alex Ferguson, British football's most successful manager, to replace him at Old Trafford following his retirement at the end of last season.
Eto'o gave Chelsea a 17th minute lead when his shot from just outside the box deflected off Michael Carrick's outstretched boot and past the despairing dive of United goalkeeper David de Gea.
The 32-year-old veteran Cameroon striker made it 2-0 on the stroke of half time when, following Gary Cahill's centre, he smashed the ball home from six yards out.
United, without injured strikers Wayne Rooney and Robin van Persie, found themselves 3-0 behind four minutes after the interval when more lax defending from a set-piece allowed Cahill a free header from a few yards.
His effort was just about blocked by de Gea but, barely a yard away, Eto'o reacted first and made no mistake with the simple chance.
In the process Eto'o become the first Chelsea player to score a hat-trick against United since Seamus O'Connell back in 1954.
Javier Hernandez, on as a substitute for Ashley Young, pulled a goal back 12 minutes from time.
But that was as good as it got for United whose misery was compounded when captain Nemanja Vidic sent off in stoppage time for a rash challenge on Eden Hazard.
Earlier, Emmanuel Adebayor scored twice as Tottenham Hotspur moved level on points with fourth-placed Liverpool after a 3-1 win away to struggling Swansea.
Adebayor's goals, separated by a Chico Flores own-goal, ensured Tottenham remained unbeaten in the league under manager Tim Sherwood, whose record now stands at five wins and a draw since the Englishman replaced sacked predecessor Andre Villas-Boas.
For Swansea, an eighth successive league match without a win left Michael Laudrup's men just three points above the relegation zone.
After Swansea's Wilfried Bony had hit the crossbar with the match still scoreless, Adebayor gave Spurs the lead, against the run of play, in the 35th minute when he headed in an excellent cross from Christian Eriksen.
And the north London side made it 2-0 in the 53rd minute when Flores turned Kyle Walker's cross into his own net with Spurs' Nacer Chadli waiting behind him.
Adebayor put the result beyond doubt 19 minutes from time when, with Swansea's defence opened up again, he turned in Danny Rose's ball across the six-yard box.
Bony scored seven minutes later with a shot from the edge of the box but it was all too late for Swansea.
"Even when they (Swansea) were having a lot of possession I thought we were the most dangerous side and it was just a matter of time before we clicked and found that final ball, and we did that many times in the second half and we could have gone on and won more comfortably," Sherwood told Sky Sports.
Sherwood said that Adebayor's rediscovered hunger and form after he became disillusioned and was marginalised under Villas-Boas was a boost both for the club and the player.
"It's great. It's obviously great for the football club and great for Ade himself, who's flying at the moment and enjoying his football."
Samuel Eto'o scored a hat-trick as Chelsea trounced reigning champions Manchester United 3-1 at Stamford Bridge on Sunday night.
To add insult to injury for United, Nemanja Vidic saw a straight red.
Chelsea moved to within two points of leaders Arsenal with Eto'o scoring in the 18th, 45th and the 49th minutes to seal a deserved victory.
Substitute Javier Hernandez pulled one back for United in the 78th minute but it did not trigger a fightback.
"In the first 15 minutes they were on top but we didn't panic, kept our shape and hit them on the counter-attack," said Chelsea captain John Terry.
The last season in which Man United lost seven league matches after 22 matches as reigning champions was 1957/58, according to Infostrada Sports.
"I think it is a big win and deserved, yes. The way I was analysing the game it was hard for them to be losing 2-0 at half time. They started better than us, they had a good initiative," Chelsea manager Jose Mourinho tells BBC Sport.
David Moyes' woes continued despite a late goal from Hernandez.
Chelsea 3 (Eto'o 17, 45, 49) Man United 1 (Hernandez 78)
A brilliant hat-trick by Cameroon striker Samuel Eto'o has given Chelsea a deserved 3-1 win over Manchester United at Stamford Bridge on Sunday.
Chelsea have given Jose Mourinho his 100th win in the Premier League. His first win in the Premier League also came against United.
90+4" YELLOW! Rafael is booked for a foul on Cahill in the dying seconds of the game.
90+2" To add insult to injury, United captain Vidic is shown the red card by Dowd for a nasty challenge on Hazard.
90" There are four minutes off added time.
90" Hernandez heads straight to Cech from the six-yard box.
88" Torres is receiving treatment after a heavy challenge while Moyes fumes blaming the delay.
87" In 2012, Chelsea led Man Utd 3-0 and ended up drawing the match 3-3. It is sure unlikely to happen this time.
85" Chelsea make their final change as Nemanja Matic replaces Willian.
82" United press forward and win a free-kick 35-yards out and they take it short to Januzaj, who gets a cross in but Cech collects.
79" Torres comes on for Eto'o who leaves the field to a standing ovation.
78" GOAL! Welbeck and Jones combine to set up Hernandez who pulls one back for United from close range.
Chelsea 3 (Eto'o 17, 45, 49) Man United 1 (Hernandez 78)
75" Torres is about to come on for Chelsea's three-goal hero Eto'o.
74" Willian cuts into the box and crosses for Eto'o but De Gea collects it.
71" Great defensive header by Terry who clears Januzaj's cross.
70" Cech under pressure after he misjudges a pass back and just manages to clear as Hernandez slides in..
69" United go close as a corner from Januzaj is heading wide by Welbeck.
68" Chelsea make their first change as Oscar makes way for Mikel.
66" Mikel is about to enter the fray.
64" Hazard cuts inside from the left and gets a shot away but Carrick flicks it away for a corner.
63" A long-range effort from Willian is hit straight at De Gea.
60" United putting pressure on the left flank through Januzaj but Ivanonic clears it out.
59" Lampard is warming up while Ramires fires over the bar from a distance.
56" United make their second change as Hernandez comes in for Young.
55" YELLOW! Valencia is booked for a foul.
53" Eto'o is only the third player to score a Premier League hat-trick this season.
51" United make their first substitution with Smalling replacing the injured Evra.
48" Chelsea force a corner after good work from Oscar who feeds Eto'o in the box.
49" GOAL! Eto'o completes a hat-trick slotting a home a header from Cahill which De Gea fails to gather cleanly.
Chelsea 3 (Eto'o 17, 45, 49) Man United 0
47" United get an early free-kick as Ivanovic fouls Januzaj on the left but Oscar heads clear.
46" United regain possession and begin as they did in the first half.Chelsea get the second half underway.
A brace from Cameroon star Samuel Eto'o has put Chelsea on top against United in the first half.
45" GOAL! Eto'o scores again latching onto a great cross from Cahill after United failed to completely clear a Willian corner.
Chelsea 2 (Eto'o 17, 45) Man United 0
44" Luiz hits the wall from a free kick 30 yards out after Willian is foul on the edge of the box.
42" Oscar fires wide with an acrobatic kick in front of goal.
39" There is a clash of heads between Luiz and Jones, but both are up.
38" Danny Welbeck has a chance in front of goal but he shoots weak at Cech under pressure from Azpilicueta.
35" YELLOW! United get their first booking as Young fouls Ramires.
31" Januzaj fires across the face of the Chelsea goal but there was nobody on the end of it.
28" Evra gets a sniff of a chance for United after shrugging off Oscar but the left-back fires into the side-netting.
25" Ramires plays in Ivanovic but his cross goes straight out.
22" Chelsea get a chance to extend their lead but Willian's corner fizzes across the box.
YELLOW! Luiz is the first man to be booked for a very heavy challenge on Valencia.
17" GOAL! Eto'o puts Chelsea ahead after slipping inside Jones and firing with a left-footed shot that got a deflection off Michael Carrick and looped over De Gea.
Chelsea 1 (Eto'o 17) Man Utd 0
14" Oscar goes down under challenge from Young
12" Eto'o heads away after Januzaj is brought down near the touchline and attempts a poor shot.
11" Chelsea attack for the first time with Ramires pushing forward, but he shoots tamely straight to De Gea.
6" United win another corner as Ramires clears ahead of Valencia. Januzaj whips it into the box but nobody makes contact.
5" United keep pressing, but Terry covers well and clears.
3" United force the first corner of the match. Januzaj and Young combine and the latter crosses but Azpilicueta heads it to safety.
2" Cech forced to make a save as Youngs shoots with his left foot from the centre.
1" United make forays in the opening minute.
Kick-off: Manchester United get the match underway.
Chelsea have won 10 of their last 11 home matches in the Premier League.
The sides are led out of the tunnel as the tension mounts to a crescendo at Stamford Bridge where David Beckham is also present.
"Getting Jones and Young back is important to us. We have to get a result here and we've picked a team we think can do that," said United manager David Moyes.
"If you have the ball, they don't have the ball and you control the game," said Chelsea boss Jose Mourinho Jose Mourinho asked how he will manage Adnan Januzaj.
Branislav Ivanovic returns from injury and will play right-back with Cesar Azpilicueta on the left.
Samuel Eto'o leads the Chelsea attack in front of an unchanged midfield.
New signing Nemanja Matic is on the bench, as is fit-again Frank Lampard.
Man United replace Chris Smalling with Jonny Evans in their defence and bring Phil Jones and Ashley Young into midfield with Darren Fletcher and Shinji Kagawa making way.
Chelsea: 1 Petr Cech; 2 Branislav Ivanovic, 24 Gary Cahill, 26 John Terry (c), 28 Cesar Azpilicueta; 7 Ramires, 4 David Luiz; 17 Eden Hazard, 11 Oscar, 22 Willian; 29 Samuel Eto'o.
Substitutes: 23 Mark Schwarzer, 3 Ashley Cole, 12 John Mikel Obi, 21 Nemanja Matic, 8 Frank Lampard, 10 Juan Mata, 9 Fernando Torres.
Man United: De Gea; Rafael, Evans, Vidic (c)Evra; Valencia, Jones, Carrick, Young, Januzaj; Welbeck.
Substitutues: Lindegaard, Smalling, Fletcher, Cleverley, Giggs, Kagawa, Hernandez.
Referee: Phil Dowd