Johannah Leedham's last-gasp shot gave Great Britain a thrilling 61-59 road win over Germany to get them off the mark in the EuroBasket qualification campaign.
Leedham sank a jumper in the final seconds to secure victory just when it looked as though the game was heading for overtime after Britain blew a late lead.
Having surrendered a seven-point advantage midway through the quarter, the Brits were up by two after Mason's jump-shot.
But Dorothea Richter's three-pointer got Germany within one and then, with 2:22 on the clock, Lisa Koop's jumper put Germany in front.
Britain turned the ball over again but Breitreiner could not capitalise as she came up empty on a long-range shot.
Leedham missed a lay-up and Breitreiner was off the mark again to keep it a one-point game going into the final 40 seconds.
Megan Moody hit a three-pointer to put Britain two ahead, but Koop responded with a jumper in the final moments left to tie the scores, 59-59, setting the stage for Leedham's dramatic clincher.
Leedham led Great Britain with 16 points, while Stefanie Collins had 11 and Georgia Jones 10.
Germany wasted 24 points from Breitreiner.
Mark Clark, head coach of Great Britain:
I'm very pleased with our victory. This gives us a lot of confidence for the coming games. It was a tough game because Germany came back so many times. But we had Johannah...
Johannah Leedham, Great Britain:
Amazing! I hit the decisive shot but it was a great team effort to win this game. Hopefully we can win some more.
Imre Szittya, head coach of Germany:
We did not lose this game in the final second. We had 17 tunrover in the first half. After a good start we lost control without pressure. We came back, but it was not enough tonight.
Alexandra Müller, Germany:
We always play some minutes withour our heads. Then we wake up too late. It costs a lot of power to come back in a game several times. Probably that's why we had no control in the final minutes. We are not clever enough.