Sam Kerr has rescued a vital point for Chelsea in Europe's biggest women's club match so far this season, with an 89th-minute goal snatching a 1-1 draw at title rivals Arsenal.

The Matildas captain was a peripheral figure for much of the top-of-the-table Women's Super League London derby, overshadowed by compatriots Caitlin Foord and Steph Catley.

Foord won a contentious 56th-minute penalty, which was converted by Arsenal captain Kim Little and looked to have won the match for Arsenal in front of around 45,000 fans packed into the Emirates Stadium for the double header with the Arsenal-Tottenham men's game.

Both Aussies went close to adding a second as Arsenal, who are bidding to break Chelsea's three-year stranglehold on a title the Gunners last won in 2019, tried to seal the match.

However, instead, Kerr — timing her jump superbly — rose behind England captain Leah Williamson to head in Jelena Čanković's cross and snatch an equaliser.

"It is a big goal in the title race," Kerr said.

"We needed something. Jelena came on and put in a great ball, I had been waiting for it for 15 minutes and I kept my cool.

"I pride myself in staying in the game for those moments at the end and it came off."

Foord said it was less fun being on the opposite side of her Matildas teammate's heroics.

"You can't stop her. I don't think anyone can," she told Forbes.

"You knew she would get one chance like that and you can't let it happen because it will end up in a goal."

The Blues only had two shots on goal compared to Arsenal's seven in the match.