Jan Bednarek's second goal in three games helped Southampton come out on top in an enthralling five-goal thriller against West Ham at the London Stadium.
It is now five games without a win for the Hammers, who came from behind twice to level, only for Saints to grab a first victory in seven league matches.
The visitors made early pressure tell inside 10 minutes as Mohamed Elyounoussi fired past a sprawling Lukasz Fabianski from the edge of the area after being fed by Kyle Walker-Peters.
Elyounoussi remained a threat on the break but squandered a good chance just past the half-hour mark.