Sloppy Liverpool lost their third Premier League game this season in a 3-1 shock at West Ham United.
Last season's runners-up Liverpool who enjoyed a winning start to their Champions League campaign this week, slipped to defeat after conceding two goals in the first seven minutes at Upton Park.
Winston Reid and Diafra Sakho put West Ham ahead and, although Raheem Sterling replied before halftime, Liverpool suffered a third defeat in five league games this season when substitute Morgan Amalfitano scored on the counter late on.
Earlier, Arsenal scored three goals in a four-minute span to beat Aston Villa 3-0 and halt the host's good start to the Premier League season.
Mesut Ozil answered critics by scoring the first goal in the 33nd minute and then setting up Danny Welbeck a minute later for the former Manchester United striker's first goal for Arsenal.
The third came shortly afterward, when Kieran Gibbs' low cross into the area was turned into the net by Villa defender Aly Cissokho as the hosts' resistance collapsed.
In the other matches, Southampton grabbed a late winner to beat 10-man Swansea 1-0, Newcastle fought back to draw 2-2 against Hull City, Burnley and Sunderland were involved in a goalless draw and Queens Park Rangers twice came from behind to also draw 2-2 with Stoke.