Ole Gunnar Solskjaer has a golden opportunity to further his credentials for the permanent manager's job at Manchester United when he goes head to head against Tottenham boss Mauricio Pochettino on Sunday.
The Norwegian interim manager has enjoyed a perfect start to his Old Trafford career, winning all five matches and transforming the mood among players and fans.
But in the opposite dugout at Wembley will be Pochettino, who remains the favourite to be named to the United hot seat after keeping Spurs on the fringes of the Premier League title race against considerable odds.
United have beaten Cardiff, Huddersfield, Bournemouth and Newcastle in the league and Reading in the FA Cup since Solskjaer replaced Jose Mourinho last month.
But third-placed Tottenham in London will be a different proposition and the match will be a severe examination of how far United have come under their temporary leader.
Solskjaer has revitalised a number of players including Paul Pogba and Marcus Rashford, but bristles at suggestions he has had an easy ride so far.
"We've had tests," he said. "Newcastle away is a test and the first game was a test as to how everyone reacted. The first home game with the crowd is a test."
"We are not going to get as many chances to attack against these as we had before so when we have the ball we have to be ready to play well with it and we have to use the whole pitch because Wembley is a decent size pitch as well," he added.
Solskjaer says he has not spoken to the club hierarchy about the full-time position although has clearly stated his desire to stay beyond the end of the season.
The minimum requirement for Solskjaer is probably to qualify for next season's Champions League -- United have closed the gap significantly but are still six points behind fourth-placed Chelsea.
But the former striker, who has United fans' undying loyalty after his exploits as a player, must see off the threat from Pochettino if he is to prolong his stay at Old Trafford.
Spurs trophy charge
Spurs have amassed 48 points after 21 matches, just two behind Manchester City and six shy of leaders Liverpool and are still competing on four fronts with Champions League, FA Cup and League Cup commitments on top of a title challenge.
Pochettino started the season with two huge challenges - no fresh signings and no proper break for many of his top stars after they were involved in the World Cup until the final weekend.
Tottenham, who beat United 3-0 at Old Trafford earlier this season, are also still waiting to move into their new stadium after months of delays.
The Argentine boss, who has yet to win a trophy as a manager, has given mixed messages over his future, refusing to rule out a move to Old Trafford but also saying he hopes to be at Spurs for 20 years.
But Pochettino believes neither he nor Solskjaer will need any extra motivation than the three points on offer on Sunday.
"Of course for him (Solskjaer) it's a massive motivation or challenge to manage Manchester United, like for me it's a massive challenge to be in front for this football club, Tottenham.
"Always the motivation is to win because we're so competitive. We're people that love to win and hate to lose, and always when you play a friendly game or a competitive game like Sunday always it's about winning."