Manchester City moved 13 points clear at the top of the Premier League as John Stones sealed a 2-1 win against West Ham that made it 20 successive victories in all competitions for the leaders.
Pep Guardiola's side are closing in on their third Premier League in four seasons thanks to priceless contributions from their in-form centre-backs.
Ruben Dias, imperious since signing from Benfica in September, put City ahead with his first goal for the club.
Michail Antonio equalised for West Ham just before half-time, but the revitalised Stones bagged the winner with a fine strike after the break.
City are enjoying the longest ever winning streak by an English top-flight team, with 14 of those 20 victories coming in the league to leave their title rivals trailing in their wake.
They are unbeaten in 27 games across all competitions.