Evra finally gave United breathing space when he headed in from close range after 67 minutes, two minutes before Wilshere was shown a second yellow card for a rash foul on the Frenchman.
United manager Alex Ferguson said he was surprised by the subdued nature of the visitors whose rather meek display was summed up by the unusual sight of Brazilian defender Andre Santos swapping shirts with Van Persie at halftime.
He was more concerned by his side’s poor finishing.
“It was a strange game, and the chances we missed,” he said. “We should have put the game to bed. If you see the scoreline you’d think it was a close game, but it wasn’t.”
“It was an unusual Manchester United versus Arsenal game. There were a lot of bookings, but it never really got anywhere near the Manchester United versus Arsenal games of the past,” he said.
Chelsea were just a few minutes away from a noteworthy victory at the end of a seven-day period that saw them lose to United in the league, beat them 5-4 in the League Cup and also find themselves embroiled in another racism storm.
Moses headed Chelsea in front after an hour, but as heavy rain began to fall at the Liberty Stadium the visitors were pushed back and Hernandez beat Petr Cech to deny Roberto di Matteo’s team victory.
“Mentally and physically it has been a demanding week,” Di Matteo told Sky Sports. “The players responded and we nearly won the game. We defended well and they didn’t create many chances although it was a quality goal they scored.”