Alessia Russo bagged the only goal of the game as Manchester United saw off Arsenal to stretch their lead at the top of the Women's Super League.
Russo netted for the ninth time in the league this season in first-half stoppage time when she was teed up by Nikita Parris.
And the right-footed strike proved decisive as United dealt a huge blow to their rivals' hopes of claiming the title.
England international Russo, 24, said: "I'm buzzing. These are the games that mean so much.
"Arsenal are a top side and these games are so important to us.
"From now until the end of the season, every three points count. This was a big one tonight."
Marc Skinner's side, who booked their place in the FA Cup final with a 3-2 win over Brighton on Saturday, have now played two games more than nearest rivals and defending champions Chelsea.
Speaking to BBC Sport, United defender Aoife Mannion stressed just how important the win was with the Blues breathing down their necks.
She said: "There are absolutely no words for that win. My voice has gone a little bit.
"Every part of my body is cramping. I'm just so glad we were able to get the result."
Worryingly for Arsenal, Leah Williamson was forced off with what appeared to be a serious injury after just 15 minutes.
With the first leg of their Champions League semi-final against Wolfsburg to come on Sunday, ex-England international Fara Williams questioned the logic of forcing the Gunners to play this evening.
She said: "I'm disappointed. We've got two English teams in the semis and the fixture schedulers could have helped Arsenal.
"This fixture did not need to be played tonight.
"To have to travel to Manchester before going away to Wolfsburg is disappointing for Arsenal."
