Manchester City suffered their first League defeat of the season, while Newcastle and Sunderland lost again.
City had come into their game on the back of five wins and without conceding, but they went behind early on through Victor Moses’ long-range strike.
Diafra Sakho added a second on the half-hour mark, and despite Kevin de Bruyne getting his first City goal on the stroke of halftime, they could not add to that tally as the Hammers go second.
Struggling north-east sides Sunderland and Newcastle United both lost. The Magpies crashed 2-1 at home to Watford, for who Nigerian Odion Ighalo netted twice. Daryl Janmaat got a consolation.
Sunderland lost 2-0 at AFC Bournemouth, for who Callum Wilson and Matt Ritchie netted to further increase the pressure on Black Cats boss Dick Advocaat.
West Brom won 1-0 at Aston Villa thanks to Saido Berahino’s first half goal, while Swansea City were held 0-0 at home by Everton.
Leicester City continued their impressive start to the season, coming back from 2-0 down to force a draw at Stoke City.
Bojan and Jonathan Walters gave the Potters a comfortable halftime lead, but Riyad Mahrez and Jamie Vardy ensured a share of the spoils.