Arsenal moved eight points clear at the top of the Premier League thanks to a routine home victory over managerless Crystal Palace.
The Gunners, aiming to become champions for the first time since 2003-04, went ahead at Emirates Stadium through Gabriel Martinelli's left-footed strike - his sixth goal in six league matches.
Bukayo Saka doubled the lead when he collected Ben White's pass and curled an effort past 19-year-old goalkeeper Joe Whitworth.
Granit Xhaka made it 3-0 with a first-time finish from Leandro Trossard's assist, before Jeffrey Schlupp pulled one back from close range following a corner for Palace's first goal in five matches.
But the excellent Saka restored Arsenal's three-goal advantage with a guided finish from Kiernan Tierney's pull-back to seal the victory.
Arsenal have 69 points from 28 matches, with second-placed Manchester City, who beat Burnley 6-0 in the FA Cup quarter-finals on Saturday, on 61 points having played a game less.
Palace, who sacked manager Patrick Vieira on Friday, have not won in 13 games in all competitions and only three points above the relegation zone.