A wonderful 17th-minute goal by Olivia Smith helped Arsenal consign Women's Super League leaders Manchester City to a first defeat since September.
City had not lost since the opening day of the season but Andree Jeglertz watched the 17-match unbeaten run of his pace-setters end at Emirates Stadium.
Smith raced onto a wonderful Mariona Caldentey pass and rounded Ayaka Yamashita to score her seventh goal for Arsenal.
Even though WSL leading scorer Khadija Shaw threatened before and after half-time, Renee Slegers' side held on for a vital three points.
Chelsea made sure to capitalise on City’s failings as they dispatched London rivals Tottenham 2-0 on enemy turf.
The Blues went ahead against the run at the Tottenham Hotspur Stadium as Keira Walsh slotted home from Erin Cuthbert’s corner on 39 minutes, giving Sonia Bompastor’s side the advantage going into half-time.
Alyssa Thompson gave the visitors daylight soon after the restart, firing home from the rebound and putting Chelsea in what would prove an insurmountable position.
The defending WSL champions remain nine points off City, however, and will need something of a miracle to lift a seventh consecutive title this term.
Liverpool moved off the bottom for the first time since November with a fine 4-1 win over Aston Villa.
It took the Reds 12 matches to get off the mark in the WSL this season, but they made it two wins in three after goals by Mia Enderby, Martha Thomas, Grace Fisk and Aurelie Csillag in St Helens.
Enderby and Thomas scored within 14 minutes and while Miri Taylor reduced the deficit before the break, Fisk and Csillag struck late on to help Liverpool leapfrog relegation-rivals Leicester.
West Ham were set to go bottom after they went two goals down at home to Brighton before they produced a remarkable turnaround to win 3-2.
Manuela Vanegas put Brighton 2-0 up after 63 minutes following Kiko Seike's 40th-minute opener, but Ffion Morgan gave the hosts a lifeline with eight minutes left when her cross caught out goalkeeper Chiamaka Nnadozie.
Shekiera Martinez levelled in the 86th minute before Viviane Asseyi completed the comeback after a goalmouth scramble in the first minute of stoppage-time to spark wild celebrations.
Everton responded to the midweek dismissal of Brian Sorensen with a 1-0 triumph at London City.
After a goalless first 45, Inma Gabarro broke the deadlock in the 62nd minute.
It proved enough to help Everton register back-to-back WSL wins for the first time this season after a string of saves by goalkeeper Courtney Brosnan.
Liverpool v Manchester City live: Team news and line-ups from Premier League
Is Liverpool vs Man City on TV? How to watch Premier League clash
Mikel Arteta: Arsenal’s Premier League lead counts for ‘nothing’
Viktor Gyokeres hitting ‘highest level’ for Mikel Arteta and Arsenal
Ismaila Sarr on target as Crystal Palace end 12-match winless run at rivals Brighton
Kieran Trippier pledges to turn Newcastle’s dire form around after latest home loss
