The score ended 2-2 after Jesse Lingard quickly canceled out Arsenal's go-ahead goal in the second half.
Shkodran Mustafi opened the scoring when David De Gea bobbled the German's headed effort in the 26th minute. It was an unfortunate turn of events for United, who were playing at a higher tempo than they had in previous matches.
Not to be outdone, Arsenal conceded a minute later. Sead Kolasinac misjudged Rojo's hopeful punt forward, allowing Lingard to pounce in the penalty area and again balance the scales.
Uncharacteristically sloppy in the first half, De Gea suddenly came to life, making several spectacular saves - including a desperate dive to deny top scorer Pierre-Emerick Aubameyang - to preserve the draw.
Arsenal felt aggrieved when Lacazette nodded the ball from De Gea's grasp and rushed to goal, but referee Andre Marriner whistled the play dead before the Frenchman could celebrate a potential winner.
The result leaves Arsenal in fifth place and United in eighth with a minus-1 goal differential.