Newcastle United closed in on the top four with a 2-0 victory at Blackburn Rovers on Wednesday and Arsenal slipped to seventh after a goalless draw at Bolton Wanderers stretched their winless run in the Premier League to four matches.
Scott Dann's own goal and a late effort by substitute Gabriel Obertan lifted Newcastle into fifth place, three points behind Chelsea, while luckless Rovers remained stuck fast in the relegation zone.
Arsenal drew 0-0 at Bolton and remain five points adrift of the top-four place that has been a virtual guarantee for the past decade under manager Arsene Wenger whose Dutch striker Robin van Persie was twice denied by the woodwork.
"The belief is there, the desire is there and the confidence is there. We have come through a difficult period and we have of course a fight in front of us but we are ready for it," Wenger said when quizzed on his side's prospects of qualifying for next season's Champions League.
"We have to hope that the fact we didn't lose gives us confidence."
Djibril Cisse needed less than 15 minutes to mark his return to the Premier League with a goal as he opened his account for Queen's Park Rangers in their 2-2 draw at Aston Villa.
The 30-year-old former Liverpool and Sunderland player, who signed on transfer deadline day from Lazio, celebrated with a somersault after smashing a shot past Villa keeper Shay Given.
QPR doubled their lead with a Stephen Warnock own goal but England striker Darren Bent halved the deficit on the stroke of halftime and Charles N'Zogbia volleyed a second-half equaliser, his first goal for the Midlands club.
"We're delighted that he has such an instant impact so early in his QPR career. You saw his quality tonight in tight areas, where he was able to use his pace and power and that will be effective for us in the course of the season," QPR manager Mark Hughes said of French striker Cisse.
Sunderland's form continued its upward curve since Martin O'Neill took over as manager with a 3-0 home victory over Norwich City that lifted them to eighth - Fraizer Campbell paving the way for a fifth win in seven league games with a spectacular volleyed opener.
Former Fulham coach Roy Hodgson returned to Craven Cottage where his West Bromwich Albion side eked out a 1-1 draw thanks to a late equaliser by Somen Tchoyi.
Champions Manchester United moved level at the top of the table with a 2-0 victory over Stoke City on Tuesday when leaders Manchester City suffered a 1-0 defeat at Everton.
Newcastle, the surprise package during the early months of the season, proved they are serious contenders for a European berth with a gritty win at Ewood Park.
After Ryan Taylor's shot deflected into the net off Dann after 12 minutes Newcastle were forced to defend for long periods as the hosts dominated.
Blackburn's David Dunn squandered the chance to equalise from the penalty spot and Rovers also struck the woodwork late on before Obertan's clincher.
"You have got to have resilience, a good keeper and a good captain and we have got that," Newcastle manager Alan Pardew said. "Blackburn create chances all the time because everything comes in your box.
"We defended with passion and with our hearts, like we have done all season and that is why we have done so well."
Arsenal, who found out earlier on Wednesday that Jack Wilshere had suffered a setback in his recovery from injury, suffered more frustration at Bolton.
Van Persie came agonisingly close to a 20th league goal of the season when his crafty lob struck the bar late on to leave Arsenal still waiting for their first league win of 2012.