Sheffield Sharks won the BBL Play-offs final for the first time in 12 seasons when they beat Leicester Riders 84-77 at the O2 Arena in London.
The Riders, who won the Trophy and the league this season, failed to score for five minutes in the last quarter as the Sharks overhauled them.
Mike Tuck, voted the most valuable player, led Sheffield's scorers with 20 points and Jerrold Brooks added 18.
Northumbria won the WBBL play-offs title with a 75-68 win over Nottingham.
Neal Watson had 19 points for Leicester and Conner Washington added 15.
Leicester were uncharacteristically untidy in the first quarter but still came out of it leading 22-18.
Sheffield's six three-pointers in the second quarter - three from Kyle Odister and two from John Barber - ensured the Sharks were ahead 44-43 at the interval.
Leicester scored the last 10 points of a tight third quarter to lead 66-59 with 10 minutes remaining but Sheffield re-took the lead, 73-71, with 4:14 remaining with five points in a row from Brooks.
When Riders' Tyler Bernardini hit a three with 6:14 remaining, Leicester led 71-66, but that was their last score for almost five and half minutes - Sheffield's 14 unanswered points in that time left Leicester scrambling for a reply they could not find in the final minute.
Meanwhile, Nottingham, the league champions, led by as many as 13 points late in the first half, but Northumbria came back to lead with six minutes remaining and held their nerve in a tense final minute to win their first WBBL trophy.
Fiona O'Dwyer led Northumbria's scoring with 17 points and Nottingham's efforts were led by Amber Stokes' 21 points.
What they said:
Sheffield forward Mike Tuck: "I couldn't be more proud of our guys - we've had such an up and down season with changes of players and losing guys to injuries - to fight all the way through the post-season to win the biggest competition of the year on the biggest stage in British basketball."
Leicester coach Rob Paternostro: "I thought we missed a lot of easy [shots] around the basket, some of them went in and out - demoralising misses for us. I thought it was quite comical that they were playing the underdog role because everyone in the league knew how good this team was."
Northumbria coach Chris Bunten: "We were down big in the first half and we weren't playing particularly well. We just said 'we can't play any worse than we are now - let's go out and play the way we can', and from that point we executed superbly."