Robin van Persie marked his return to Arsenal by scoring a penalty amid a chorus of boos to give newly crowned Premier League champion Manchester United a 1-1 draw on Sunday that also hurt his former team's chances of making the Champions League.
Arsenal fans had already had to watch their team form a guard of honor for Van Persie and his United team before kickoff at the Emirates Stadium to salute the new champions.
The crowd then reveled in Van Persie giving the ball away inside two minutes to allow Theo Walcott to put Arsenal in front. But after Van Persie was brought down by Bacary Sagna just before halftime, the former Arsenal captain sent the spot kick into the net.
It was Van Persie's 31st goal this season since defecting last August in a 24 million-pound (then $36 million) transfer.
The draw meant Arsenal was dislodged from third place by Chelsea, which beat Swansea 2-0 as it looks to secure one of the top four Champions League qualification spots.
And United, which is yet to be presented with the Premier League trophy, now cannot surpass Chelsea's record tally of 95 points with three games left.
What made Van Persie's return to Arsenal more galling for the home fans was the fact he has won the league in his first season when they haven't seen the trophy lifted since 2004 when they were still playing at the nearby Highbury.
In fact the Gunners haven't won anything since the 2005 FA Cup in Van Persie's first season with the team.
The striker is so accustomed to the north London club that he attempted to walk into the home dressing room by mistake before Sunday's game, and then slapped his head as he realized his mistake.
Whether it was a genuine mistake or a prank, Van Persie has had the last laugh.
Tradition dictated that the Arsenal players lined the pitch next to the tunnel to welcome United, which clinched its 20th English title on Monday with a victory over Aston Villa.
Such respect ended immediately after kickoff.
And it will have be pleasing for Arsenal that it was Van Persie who gave the ball away in midfield so quickly, and Tomas Rosicky then picked out Walcott, who smashed in a low shot past goalkeeper David De Gea.
The hosts, with a Champions League place to fight for, were playing the slicker more incisive football.
And as they pushed for another goal, Santi Cazorla tried his luck from distance, drawing a save from De Gea.
Arsenal was exerting the control so lacking at times in this season, which saw the team get off to its worst start since Arsene Wenger took charge in 1996.
United, meanwhile, seemed sluggish after the week's title celebrations.
When Van Persie worked his way down the left and sent in a cross, the finish was weak from Phil Jones, whose header missed the target.
As the encounter heated up, Van Persie was booked for a sliding challenge on Per Mertesacker, and United defender Evra squared up to Walcott.
Van Persie was first denied a goal when his close-range header from Evra's cross was blocked by goalkeeper Wojciech Szczesny rushing off his line to make the save with his face
But then it was Van Persie's turn to capitalize on a mistake as he intercepted Sagna's poor back pass and raced clear into the area, where the defender brought him down with a sliding challenge in the 44th.
Van Persie was clinical from the spot, but his celebrations were muted as he reached 25 league goals for a second successive season. He also scored against Arsenal at Old Trafford and equaled his feat from last season when he also scored in both fixtures between the teams - although that time for Arsenal.
Arsenal, though, made an assertive start to the second half, with Rosicky curling wide inside a minute.
But they couldn't produce a winner.
United was denied by poor finishing and Szczesny blocking Wayne Rooney's downward header.
De Gea preserved the point for United late on by tipping Cazorla's powerful shot wide.
Information from Press Association and The Associated Press contributed to this report.