West Ham boss Manuel Pellegrini has warned Marko Arnautovic to knuckle down and focus on football next season.

Arnautovic scored his first goals since January as the Hammers swept aside Southampton 3-0 in their final home game of the season.

The temperamental Austrian's form deserted him after his unseemly attempt to secure a lucrative switch to China during the transfer window.

Arnautovic has even been booed by West Ham fans for his indifferent displays since the proposed move failed to materialise.

But the forward was back to his menacing best with two goals as the Hammers secured their biggest home win of the season.

"With this team, with Marko, a complete season that is quiet, calm and just playing football, he is a player who makes a difference," said Pellegrini.

"I'm sure this season will be a good lesson for him, he learned some things. I am absolutely convinced next season we will see a great Marko."

Arnautovic grabbed the first in the 16th minute after Mark Noble capitalised on a mistake by Yan Valery to put him through one-on-one with Fraser Forster.

The second arrived midway through the second half after Forster's block ricocheted off Arnautovic and looped into the air for a free header.

Moments later Ryan Fredericks lashed in number three for his first Premier League goal as West Ham, 1-0 winners at Tottenham last weekend, made it back-to-back victories.

"I talked with the players before the game and told them that after an important victory against Tottenham the best way to finish was winning in front of our own fans," added Pellegrini. 

"It's important to enjoy these moments."

Southampton had secured their survival last weekend and their lacklustre performance came as no shock to manager Ralph Hasenhuttl.

"It's not a coincidence that after some intense weeks and months, using that energy to stay in the league, and then you have a game today where you make a big mistake and go 1-0 down, that the physical energy is not so high," said Hasenhuttl.

"That's not a surprise to me. The power and conviction was not there. We have invested a lot. You could feel we were not that compact and a few steps too late.

"After the second goal the game was gone. That was the knockout. I know if you give Arnautovic space he is very clinical. The first goal is perfect for him, we made it too easy for him."