Arsenal and Tottenham have kept up the pace in their pursuit of a Champions League place.
But while the London rivals' wins ensured it was 'as you were' in the top-four battle, the relegation scrap at other end of the Premier League only got tighter on Sunday.
Arsenal remained in fourth after Gabriel's header secured a 2-1 win at West Ham to stay two points ahead of Spurs, who had earlier beaten Leicester 3-1 with a Son Heung-min double.
Chelsea still look well-placed to qualify for the Champions League despite now being only three points ahead of Arsenal with four games remaining, but they were left smarting with a shock 1-0 defeat at Everton.
It's a result - secured by Richarlison's goal - that gives Everton renewed hope of avoiding relegation after a 68-year stay in the top division.
Everton moved two points from safety with five matches to go and a game in hand over both Leeds and Burnley, who are just above the drop zone.
Richarlison's four goals in his last five league matches match the amount he scored in his first 21 games of the season.
The latest came 59 seconds into the second half at Goodison Park, but the Brazilian could face Football Association action after picking up a lit blue flare during his goal celebrations and throwing it back into the stand.
Everton relied on Jordan Pickford's saves to preserve the win -- denying Cesar Azpilicueta, Ruben Loftus-Cheek and Thiago Silva.
"We're still in a massive scrap," captain Seamus Coleman said. "We've got to keep going and keep battling."
Third-place Chelsea have only four points from four games.
"We struggle to play without big mistakes," Chelsea manager Thomas Tuchel said. "And that is why we struggle to have results."
For Spurs, Son is now on a career-high 19 Premier League goals this season, only three behind Liverpool striker Mohamed Salah in the race for the Golden Boot.
Before scoring against Leicester, Son also provided the opener in the 22nd minute by delivering a corner for the unmarked Harry Kane to head into the bottom corner to end a five-game goalless run.
"We are talking about a great player, fantastic player," Spurs' boss Antonio Conte said of Son, who scored in the 60th and 79th minute.
Kelechi Iheanacho scored a stoppage-time consolation for Leicester, who are 11th and looked more focused on their Europa Conference League semi-final against Roma on Thursday after drawing 1-1 in the first leg.
Seventh-placed West Ham's focus is on Europe too, with their second-leg game in the Europa League semi-finals against Eintracht Frankfurt on Thursday.
But Arsenal still found it hard going before Bukayo Saka's corner was headed in by Rob Holding in the 38th minute for his first-ever Premier League goal in six years.
Jarrod Bowen levelled from close range before the break but Arsenal went in front again nine minutes into the second half when Gabriel Martinelli crossed to an unmarked Gabriel for a diving header, earning Arsenal a third win in a row.
Australian Associated Press
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