Arsenal and Tottenham Hotspur both posted victories as the race for fourth place in the Premier League intensified on Sunday.

Tottenham returned to form as Son Heung-min scored twice and Harry Kane once in a 3-1 victory over Leicester City.

That briefly elevated Tottenham into fourth place, above Arsenal who responded impressively to win 2-1 at West Ham United with goals by defenders Rob Holding and Gabriel.

Arsenal's third successive league win after three straight defeats moved them to 63 points from 34 games with Tottenham's first win in three leaving them on 61 from 34.

Third-placed Chelsea are not totally assured of a top-four finish after they lost 1-0 at Everton -- a vital result for the hosts in their bid to stave off relegation.

Striker Richarlison sealed victory at a rocking Goodison Park a minute into the second half after Cesar Azpilicueta gave up possession under pressure from the Brazilian forward.

Everton remain third from bottom but are only two points behind 17th-placed Leeds United having played a game less.

Chelsea have 66 points from 34 games.

Everton manager Frank Lampard, Chelsea's record scorer and former manager, knew how big the win against his old club was.

"Today was a huge game for us and when you see the fans turn up before this game and what they did to this game -- they were people of the match," he said.

"Men, women and youngsters, all Everton crazy, they love this club and they pushed us over the line.

"We are still in the relegation zone, we have the extra game but we have to go with that same spirit in every match."

Tottenham knew that only a win at home to Leicester would be good enough after losing to Brighton & Hove Albion and drawing with Brentford in their last two games -- two dismal displays that put a huge dent in their top-four hopes.

They responded with a vibrant display capped by two goals for Son who is in the race for the Golden Boot award.

Son has scored 19 league goals this season, three fewer than top scorer Mohamed Salah of Liverpool.

Son's corner allowed Kane to put Spurs ahead with a thumping header and he then made sure of the points with two quality finishes after the break, both assisted by Dejan Kulusevski.

"We got three points in an important moment of the season especially as in the next games we are going to face Liverpool and Arsenal," Tottenham manager Antonio Conte said.

Arsenal are now sensing a first top-four finish since 2015-16 and manager Mikel Arteta praised his side's ability to win ugly after grinding out the points at West Ham.

Holding headed in Bukayo Saka's corner to break the deadlock in a tame first half but Jarrod Bowen's deflected shot levelled it up before the break at the London Stadium.

Gabriel's diving header earned Arsenal the win though.

"Massive win because we put ourselves in lots of problems with our decisions in possession," Arteta said.

"But the team showed huge character not to give up and to do the right things. The way we defended it was phenomenal. From my point of view today we won ugly but I'm extremely happy."

West Ham can no longer finish in the top four but all their focus is now on next week's Europa League semi-final second leg away to Eintracht Frankfurt, having lost the opener 2-1.