Arsenal's grip on the Women's Super League crown slipped as they were held to a goalless draw by lowly Lincoln.
In a dress rehearsal for next month's Continental Cup final, the Gunners could not find a breakthrough.
That handed the title initiative to leaders Liverpool, who are now four points clear at the top.
Arsenal have a game in hand, but victories for the Merseysiders in their final two games of the season would assure them of a first title.
The Gunners, top-flight champions for the past nine years, could even miss out on a top-two place and qualification for next season's Champions League.
Bristol Academy's 3-1 win at Chelsea means the West Country team are two points behind Arsenal with a game in hand - and they could overtake the champions when the two sides meet on Sunday.
Arsenal 0-0 Lincoln
Failure to take chances cost Arsenal dear in an encounter they should have won.
In the early stages, striker Danielle Carter shot straight at goalkeeper Karen Bardsley and playmaker Kim Little fired over the bar.
Bardsley also saved comfortably from midfielder Katie Chapman's header as the Gunners continued to misfire in front of goal.
Lincoln were having a decent share of possession but, despite some neat approach play, were not causing goalkeeper Emma Byrne any serious problems.
Carter finished poorly again three minutes into the second half, the striker racing clear of the Lincoln defence but shooting tamely at Bardsley.
Right-back Alex Scott went closer, having a goalbound effort cleared off the line by Lincoln defender Martha Harris.
Midfielder Jordan Nobbs then sent a shot against the crossbar as Arsenal began to build the pressure.
But they were almost caught out when Lincoln winger Jess Clarke beat the offside trap to force Byrne into an excellent save.
Arsenal threw players forward late on in a desperate attempt to grab a winner, but they could not break down the resolute Imps.
Chelsea 1-3 Bristol Academy
Bristol had the game as good as won with three goals in the opening 37 minutes.
Natasha Harding cleverly chipped in the first, then provided the cross for Natalia to sweep home the second.
Alex Windell struck goal number three when the Chelsea defence failed to clear a throw-in.
As the Blues looked to hit back before the interval, Rosella Ayane volleyed narrowly wide.
But she did find the target four minutes after the break to reduce the arrears.