25 May 16
A competitive pool of 22 players will battle it out to represent Great Britain at the U20 European Championship Division B in Greece this summer.
It means Damian Jennings' side can secure a place in the second round if they see off Latvia in Trélazé on Sunday.
And the Englishman believes his squad have reached their peak at just the right time. "The thing we are most proud of is that we dealt with the momentum change when Serbia's press was causing us problems," said the GB head coach, following his first competitive international at the helm.
"We managed to deal with that over a period of time when it started to look like it was going their way. But some of the DNA that has been part of our existence in Great Britain, since (predecessor) Tom Maher took over particularly, has meant that we never give up.
"More than that, you can work hard but to make the decisions under pressure is another thing."
The Serbians applied plenty of that with the lead changing hands eight times until GB came out on top.
Having taken an 18-13 lead at the end of the first quarter, Cardiff-based guard Stef Collins hit a three-pointer to ignite a 7-0 run early in the second period.
But Serbia turned up the heat, forcing turnovers with their defence, to hit back with a 10-2 burst.
Britain applied pressure of their own, however, shutting down the opposing offense for three minutes to build up a 33-27 lead.
Yet Serb guard Milica Dabovic hit six consecutive free throws during an 11-3 run that slashed the gap to a single point before Collins, almost impossibly, dropped in a shot that put GB 41-38 in front at half-time.
It proved a titanic second half. Britain went over four minutes without scoring as eleven points in a row went against them.
It set them a challenge, admitted Stewart, the young London-born centre. "We knew from the start that Serbia was a great team, very aggressive and they'd come out ready. They made a great run with their press and we struggled a little bit. But we bounced right back."
Although her side trailed 59-52 headed into the final period, they saved their best to last.
Promising forward Ella Clark, in her major tournament debut, brought GB within one point with a three and then Rachael Vanderwal added another to put Jennings' side up 67-65 with three minutes left.
They never trailed again, Chantelle Handy capping a solid performance with a final basket and Jo Leedham polishing off a double-double of 12 points and ten rebounds.
"To open with a win is amazing and it just shows how far basketball in Britain has come amongst females," added Leedham, the Cheshire-born guard.
"This is a real confidence-booster. It is kind of a mental thing for us, it's all about belief, so getting this win gives us confidence and we are coming for everybody. Our style is gritty and tough. It's not pretty but we get the job done."
Group C's other game on Saturday sees France face Latvia (8pm BST).