Emery’s men went into the game with four points behind Arsenal and needed to win to close the gap on the table.
However, they failed to take advantage of the Gunners' slip-up against Everton and suffered a 2-1 defeat to Aston Villa.
As it happened
Ola Aina and Taiwo Awoniyi did not make the trip to Aston Villa after he suffered a calf injury in their 1-0 win against Manchester United.
Aston Villa scored two goals in quick succession in the first half to take the lead. Morgan Rogers scored the first from a brilliant shot and Donyell Malen scored the second from a close-range effort.
In the second half, Nottingham Forest got a goal back to reduce the deficit to one from Jota Silva, whose deflected shot from inside the box went past the helpless Emiliano Martinez.
Forest tried to get the equaliser but could not get past the Aston Villa defenders as Unai Emery’s men held their ground for the victory.