Manchester City have overturned a 1-0 deficit to lead Liverpool 2-1 in their Boxing Day clash at the Emirates.
The hosts almost got off to the perfect start when Jesus Navas guided a header on to the outside of the post and wide after Alvaro Negredo could not reach the ball.
Luis Suarez set up a counter-attack after making an interception, but after he found Raheem Sterling the youngster had the ball pinched off his foot by a sliding Aleksandar Kolarov.
Sterling then did have the ball in the back of the net, but his strike was ruled out for offside despite him being about a yard on.
He was involved with the opener, however, as he raced on to Suarez's flicked pass to cut across for Philippe Coutinho, who rolled the ball into an open net.
Liverpool were not ahead for long. Just after the half-hour mark Vincent Kompany got a yard on his marker from a corner to head down past Simon Mignolet for the equaliser.
Then, just before the break, Alvaro Negredo somehow squeezed a weak effort past Mignolet to put his side ahead at the interval.