Warren Joyce opted for a youthful line-up which included Joel Castro Pereira, Donald Love, Ben Pearson, Joe Rothwell, Saidy Janko and James Wilson. Yet there was plenty of maturity to admire in the visitors' play and no surprise when a bright opening yielded an early goal.
The advantage was played when Janko was fouled by Gedion Zelalem and, when Love returned the ball to the Swiss wide man, the fact he was inside the box did not deter Zelalem from flattening his opponent again. It was an obvious penalty and Cole stepped up to rap an unerring spot-kick into the corner of the net.
Eisfeld and Benik Afobe mustered attempts in response and the German was then spared an embarrassing miss when being flagged offside. United almost added to the lead when Wilson collected a Rothwell pass and clipped a shot off target after advancing forward with his usual menace.
Showing impressive control on a difficult surface, the Reds had a grip on proceedings until the Gunners began to make headway with a spell of pressure. Right-back Tafari Moore escaped down the right and delivered a perfect cross for Eisfeld to sweep in the equaliser from around the penalty spot.
Back came United in front of 789 fans and, after Cole shot well wide, Wilson was brought down by Semi Ajayi as he raced through with a free-kick awarded right on the edge of the box and the defender booked. Unfortunately, Love's set-piece was straight into the wall and Janko blazed over soon afterwards.