Trailing to Didier Drogba’s first league goal for Chelsea in two and half years, United appeared on the way to another demoralising defeat, and their visitors to a victory that would have moved them six points clear at the top of the Premier League, eight points above defending champions Manchester City.
But Branislav Ivanovic tripped Angel Di Maria near the left-hand corner flag, harshly earning his second yellow card and a dismissal in the process, and United were gifted one last lifeline.
From Di Maria’s resulting free-kick, Marouane Fellaini powered a strong header goalwards, which was superbly saved by Thibaut Courtois on the Chelsea goal line, but van Persie responded instantly, lashing onto the rebound and blasting the ball into the visitors’ goal.
Given United’s perilous fall from grace in the past 18 months, moments such as this have become rarities at Old Trafford and with a derby visit to the Etihad looming on Sunday, this performance and result may prove to be of far more worth than the solitary point in the league table.
It was a thrilling end to an absorbing game and one which Chelsea, who had dropped only two points all season prior to their visit to Old Trafford, will feel they should have had wrapped up even before the late heroics.
Certainly, once Drogba had broken the deadlock after 52 minutes, it was hard to envisage any outcome other than a victory for the leaders. Drogba, appearing in his sixth league game since his return to Stamford Bridge, had only played a muted role in proceedings until that point but the goal was a vintage example of the finishing that made him a Stamford Bridge legend.
The breakthrough came from a corner, won after David de Gea made a superb save to keep out Eden Hazard after the midfielder exchanged passes with Drogba and bore down on goal, only to be denied from 12 yards. However, Chelsea did not have long to wait to make amends. From Cesc Fabregas’s ensuing corner, Drogba lost his marker Rafael and steered a powerful, angled header into the United goal, via the head of van Persie.
It was turning into the perfect reunion for Mourinho, facing Louis van Gaal, his former coach at Barcelona for three years, for only the second time in their illustrious careers.
Having won their only other meeting, the 2010 Champions League final between Inter Milan and van Gaal’s Bayern Munich, nothing had occurred until that point to suggest Mourinho would not repeat the feat here.
The pair embraced warmly in the United dugout before kick-off although their respective demeanours were in stark contrast over the 90 minutes that followed — Mourinho prowling the technical area, Van Gaal glued, as usual, to his seat.
The furious note taking that has become the hallmark of Van Gaal’s management style from his position on the bench would have made interesting reading at the end of a relatively even first half, in which Courtois had saved superbly from van Persie, after a neat exchange of passes with Adnan Januzaj, and United had survived a strong penalty appeal after Chris Smalling appeared to throw Ivanovic to the ground at a corner.
There had also been a late chance for Drogba, whose 10-yard shot was well saved, and Chelsea carried that momentum into the second period, with United under intense, early pressure.
The goal, Drogba’s first in the league for Chelsea since scoring against Stoke in March 2012, underlined their growing superiority and chances continued to come with Willian first testing David de Gea from distance then just missing the target from similar range.
There was also an enterprising run from Ivanovic deep into the United area before his driven, cross-shot just flew beyond team mate Hazard and de Gea’s far post.
But referee Phil Dowd’s officious handling of the game, which so infuriated Mourinho, was also seeing the official working overtime in the card department. Somehow, in a contest which featured few if any violent or malicious fouls, the referee was on course to make nine cautions, one of which was a yellow for dissent shown to Ivanovic after he was judged to have fouled Di Maria after 65 minutes.
As Chelsea seemed content with their one-goal cushion, United could sense they might have one last throw of the dice and the introduction of substitute striker James Wilson added some energy to their efforts. The youngster headed onto the roof of the Chelsea goal, just after van Persie had been denied by the outstretched legs of Courtois, a foretaste of the late drama.
MANCHESTER UNITED (4-1-4-1): De Gea 8; Rafael 6, Smalling 6, Rojo 7, Shaw 6; Blind 6; Di Maria 6, Mata 6 (Wilson 67, 7), Fellaini 7, Januzaj 6; Van Persie 7.
CHELSEA (4-2-3-1): Courtois 7; Ivanovic 7, Cahill 7, Terry 7, Luis 7; Fabregas 6, Matic 9; Willian 8 (Zouma 90), Oscar 6 (Mikel 67, 6), Hazard 7 (Schurrle 89); Drogba 7.
Referee: P Dowd.