Alexis Sanchez scored twice as title-chasing Arsenal beat relegation-threatened Hull in controversial circumstances in the Premier League.

The hosts had been on top when the ball came off forward Sanchez's hand and ended up in the net on 34 minutes. He added a penalty in injury-time which was awarded after Sam Clucas was sent off for handball from Lucas Perez's header.

In between, Hector Bellerin and Sanchez both failed to hit the target with efforts and Mesut Ozil volleyed over the crossbar for Arsenal.

Striker Oumar Niasse had Hull's best chances - his header and low strike forced Petr Cech into a sharp saves - while Adama Diomande nodded over late on.