After a forgettable first half, Mateta opened the scoring three minutes after the restart as he latched on to a throughball from Eberechi Eze and fired low past West Ham goalkeeper Lukasz Fabianski from outside the box.

West Ham was reduced to 10 men after Konstantinos Mavropanos received a second yellow card in the 80th minute for a high boot on Mateta before the Frenchman sealed the win for the visitors from the penalty spot.

Substitute Eddie Nketiah was fouled by Fabianski inside the box and Mateta converted the spot-kick in the 89th minute to bag his fourth goal in three league games.

The derby victory helped Oliver Glasner’s side leapfrog West Ham to 12th place with 27 points from 22 matches, while Graham Potter’s West Ham is one point behind in 14th place. 

Mateta and Eze were once again instrumental for Palace as it continued its good run of form at London Stadium.

Eze has now provided eight assists for Mateta in the Premier League, with no Palace player assisting a team-mate more often in the competition's history.

It was also the third consecutive game in which Eze had bagged an assist for Glasner's side.

Mateta, meanwhile, is Palace's top scorer with eight goals in the Premier League this season and 11 overall.

He has now scored 32 league goals for Palace, but the opening goal here was the Frenchman's first to be scored from outside the box.

Crystal Palace boss Oliver Glasner heaped praise on Mateta after win.

"He gets the penalty and scores the goal, but he is also hard-working. He is a lovely guy and always so happy in the dressing room," the Austrian said of his French star.

Palace has now gone seven consecutive away games without losing for the first time in its history, winning four and drawing three during the period. 

"It's big progress. We talked about it at the beginning of the season when we struggled with different things, but it is a great group to work with, they always listen," Glasner said of the Eagles' recent form.

"It's still January but for us, it is about staying humble and keeping, to try and get the result. We have three wins this week so [the players] get a little bit more time off than planned."

West Ham fell to its second defeat in three games under new coach Graham Potter and ending the game without a single shot on target will raise concerns for the new boss.

"The game looked like it was a game too far in a long week for us. We're disappointed with the result, of course, and the performance. We weren't able to show our quality," Potter said.

"I don't think we could ever really get full control of the game. We struggled to create and sustain as many attacks as we would like. The better team won on the day, and we have a lot to improve, and we will do that by sticking together."