Sunderland clinched the Women's Premier League title with a 3-2 win at struggling Millwall Lionesses.
A late Abby Holmes goal gave the Black Cats their first major trophy and some consolation for their failed bid to join the Super League.
The historic first trophy triumph arrived 10 days before the start of the first Super League season.
Manager Mick Mulhern said: "The achievement hasn't sunk in yet, but I'm delighted for everyone involved."
He added: "We're still frustrated that we're not in the Super League, but you can only win what's there for you and it's been a great effort by the girls.
"We wanted to show everybody that we're the best team outside the Super League and I think we've done that."
In the weekend's only other league game bottom of the table Barnet boosted their survival hopes with a 3-0 win against Leeds United.
Millwall Lionesses 2-3 Sunderland
Natalie Gutteridge headed Sunderland into a second minute lead, but the visitors were then made to sweat for their priceless victory.
Goals by Lindsey Morgan and Emma Beckett gave Millwall a 2-1 interval lead and it took a spectacular 40-yard drive by Kelly McDougall to bring the Black Cats level.
As the final whistle approached it seemed they would have to settle for a point, but two minutes from time Holmes headed home the most important goal of the season.
Barnet 3-0 Leeds United
Vicky Boardman bagged a brace as Barnet lifted themselves to within two points of the safety places and with a game in hand.
Holly Sandow hit a 76th minute goal to double the 20th minute lead given the Bees by Boardman, who then completed the scoring in stoppage time.