Manchester City's thrashed bitter crosstown rivals Manchester United 4-1 in their Premier League clash, with Sergio Aguero bagging a double.
The Argentine striker volleyed City ahead after 16 minutes at the Etihad Stadium, and made it 3-0 at the start of the second half, after Yaya Toure scored on the stroke of half-time.
United's defence was sliced open again when Samir Nasri volleyed home after 50 minutes.
Wayne Rooney earned some consolation for United, scoring with his curling free kick.
In Monday morning's other matches, Arsenal jumped to the top of the league with a 3-1 home win over Stoke City, while Tottenham sit behind them after a 1-0 win at Cardiff.
Crystal Palace also beat Swansea 2-0.