London Lions became Britain’s first European champions when they defeated Besiktas 81-70 to claim the EuroCup at a packed Copper Box Arena.
The Turkish side held a seven-point lead from the first leg in Istanbul and had a two-point aggregate advantage heading into the final seconds.
But Holly Winterburn’s three-pointer and two free-throws from Megan Gustafson sealed a famous Lions win.
Karlie Samuelson scored a game-high 19 points and was named the final’s MVP.
She said: “I’m so proud of us. We didn’t come out how we needed to in the game in Turkey but we fought there, and that fight led us to this trophy.
“When Holly took that shot I felt in my soul it was in; we’re a really close team and everyone stepped up.”
Having lost the first leg in Istanbul 75-68, the Lions needed to win the second leg by eight points to claim the trophy.
No British side had reached the final of a European basketball competition before, with the London Lions men’s team eliminated in the semi-finals two weeks ago.
The Lions took a 23-17 lead into the end of the first quarter as they started the match strongly, and extended that to 45-35 at half-time.
But Besiktas had pulled it back to a five-point game at 60-55 by the end of the third quarter, knowing that gap would be enough to win them the trophy.
But Winterburn and Gustafson’s late scores in an incredible end to the match sealed the comeback win.
Winterburn, 23, who will leave the club at the end of the season, said: “It went down to the final possessions – they made some big shots at the end, but we earned this.
“We deserved this, we’ve practiced hard every single day. The group has stuck together, I don’t think I’ll ever play in a team like this again.
“With the funding situation, it’s not an option [for me] to stay and I’m sad about that. I can’t thank London enough for what they’ve done for me and British basketball.”
Winterburn and Great Britain captain Temi Fagbenle are among the players who will leave the club at the end of the season, with the Lions now unlikely to play in European competition next year because of a lack of funding.