Two goals from Marko Arnautovic and Ryan Fredericks's first Premier League strike helped West Ham beat Southampton 3-0 at London Stadium on Saturday to complete their first league double over the Saints since 2001.
Austrian Arnautovic, who had last found the net on Jan. 2, bagged the opener after Yan Valery misdirected a 16th-minute pass to Mark Noble. The midfielder slipped the ball through for Arnautovic, who produced a typically clinical finish past Fraser Forster.
Southampton's keeper was back between the posts for the first time since December, 2017 and will be disappointed with his failure to clear danger ahead of Arnautovic's second on 69 minutes.
Forster only succeeded in punching the ball at the striker who headed home from close range for his fifth goal against the Saints in as many games. Fredericks completed the rout, firing home after a clever one-two with Jack Wilshere three minutes later.
Before the Hammers' second-half goal burst, Southampton had looked the more likely to score, with the lively Nathan Redmond, who had replaced Danny Ings at the interval, forcing a fine save from Lukasz Fabianski.
But the visitors always looked vulnerable to the counter-attack and Arnautovic went close to securing his hat-trick when he curled a late shot wide.
Arnautovic's goals were his first since his abortive attempt to leave mid-season and take up a lucrative contract in China.
"It's a nice finish but it's still not the end, there's one game to go," he said. "The manager kept saying we must win this last game at home, the fans wanted to see that, we did a great game, we're happy and I think the fans are also.
"We played very well, defensively, in midfield, attacking -- we created a lot of chances."
Southampton manager Ralph Hasenhuttl suggested his team experienced a reaction after the huge effort of securing their Premier League status.
"The last very hard four or five months has cost us a lot of energy for this team and we didn't have enough energy to fight back after a horrible mistake in the first half," he said.