Southampton moved into second in the Premier League on a bad day for champions Manchester City.
Wilfried Bony's brace helped Swansea seal their first win in six Premier League games with a 2-0 win against Leicester.
Real Madrid staged a stunning El Clasico fightback to overcome arch-rivals Barcelona 3-1 at Santiago Bernabeu.
Manchester United will aim to prove their own title credentials when they welcome Chelsea to Old Trafford on Super Sunday.
Costly errors from Wes Brown and Vito Mannone helped Alexis Sanchez to a brace in a 2-0 win for Arsenal at Sunderland.
West Ham put a severe dent in Manchester City's title aspirations after earning a deserved 2-1 win at Upton Park.