A late Olivier Giroud header cancelled out Juan Mata's opener and earned Arsenal a scarcely deserved point at Old Trafford.
The Gunners had been outplayed throughout but salvaged a point when fellow substitutes Alex Oxlade-Chamberlain and Giroud linked up as the former crossed for the latter to power home a header and earn a share of the spoils.
United were again left to rue their bad luck after referee Andre Marriner had earlier waved away appeals for what looked a stonewall penalty after Nacho Montreal had rugby-tackled Antonio Valencia.
Petr Cech had made two impressive saves but Mata's well-taken opener, on 69 minutes, looked to have moved us to within three points of the visitors until the late sucker-punch.
Mata - who continued to underline his importance to the side - went close with a free-kick early on and Alexis Sanchez, selected in a lone striker's role, should have done better with a header on the quarter hour mark.
Then came the big talking point of the first half as Valencia raced through in goal and shaped to pull the trigger before Montreal hauled him down only for referee Mr Marriner to remain unmoved.
Czech saved well from Mata and then denied Anthony Martial twice in quick succession shortly before the break, as United upped the ante in search of the opener.
The Reds continued to press, without really troubling Cech further, until the deserved breakthrough arrived with twenty minutes to play.
Paul Pogba picked out Ander Herrera down the right and he cut the ball back for the onrushing Mata to fire home a low finish from 18 yards.
It was a carbon copy of the Spaniard's recent winner against City in the cup and continued his knack of scoring crucial goals in tight, high-profile matches.
Substitute Daley Blind picked out Marcos Rojo with an expert cross but the Argentine nodded narrowly wide, while Ander Herrera and Marcus Rashford both had good chances to settle the contest.
Despite the slender nature of United's lead, they seemed on course for victory with Arsenal having barely threatened, but then came the sucker-punch.
Oxlade-Chamberlain skipped past Rashford down the right and crossed for fellow substitute Giroud to power his back-post header beyond David De Gea with the visitors only attempt on target.
It was harsh on United who had dominated throughout - just as against Stoke and Burnley recently - but Jose, who remains unbeaten in his 14 league and cup matches against fierce rival Wenger, can take some positives from another excellent display.
Overall team performance: 8/10
United Faithful Man of the Match: Antonio Valencia