He hit 72 off 28 balls
in the first T20I against England in Bristol, including eight sixes to keep them in the hunt while attempting to chase 235. They fell a long way short, pegged back by regular wickets, but his innings announced him as one of the world's most talented young T20 batters and was enough to give England a real fright.
He was brutal against England's seamers, but particularly when facing their spinners: he carted 33 off ten balls against them, hitting Moeen Ali hard and flat down the ground and over extra cover, then hitting boundaries either side of the wicket off Adil Rashid. He is tall and powerful, with a long reach, fast hands and quick, snappy wrists which his Warriors coach, Robin Peterson, suggests come from his background as a golfer and a hockey player.
"Even in training, he'd shown us what he's capable of doing, so we weren't really surprised to see what we saw today," Lungi Ngidi said. "I've bowled to him myself and I've been on the receiving end of what you guys saw tonight. He's a very confident chap.
"You can see he's a big guy as well, and strikes the ball well. That's how he plays cricket. What you saw tonight is what he practises and he put that into play. That's why we weren't surprised to see what he was doing. I'm very happy for him to finally get a chance to go out and bat, and show the world what he's capable of."
Stubbs is only 21 and is still studying for a marketing and business management degree at Nelson Mandela University, but has been thrust into the limelight over the past nine months. He is not a natural interviewee and looked almost overawed when stood alongside James Anderson, Isa Guha and Colin Ingram on the BBC's coverage, but there were no evident nerves when batting.
Stubbs was the standout batter in CSA's T20 Challenge last year, averaging 48.83
at a strike rate of 183.12 for Warriors and while a similar season might have slipped under the radar a decade ago, scouting among T20 franchises has improved hugely, to the extent that Mumbai Indians were willing to take a punt on him as a replacement player in this year's IPL.
"He looks a very, very good player. He hits the ball clean and the role that he's come in, it's not easy sometimes"
Moeen Ali on Tristan Stubbs
He made 0 and 2 in his two innings at the IPL but Mumbai have kept close tabs on him: he warmed up for this series by playing for a Reliance team - effectively a Mumbai Indians academy side - against county second XIs. He looks certain to be retained for IPL 2023, and is a good bet to be signed for the Reliance-owned Cape Town franchise in the new South African league too, alongside his compatriot Dewald Brevis.
"He looks a very, very good player," Moeen said. "He hits the ball clean and the role that he's come in, it's not easy sometimes. He hit some massive sixes tonight. You're always worried about someone like that, when he's in and playing the way he's playing.
"I played against him in the IPL and he didn't get any runs but I've heard that he's a very good player. A lot of South African players talk very highly of him, and Brevis as well. They're both obviously exciting young players but he looks like a really good player."
His next challenge will be to manage the scrutiny that international cricket brings, not least in terms of planning. Eoin Morgan, England's ex-captain, suggested on Sky that England had "strayed too straight" and that they should bowl wider to stay out of his arc on Thursday night in Cardiff. "I'm sure we'll have plans for him and talk about him tonight," Moeen said. "Hopefully, that won't happen again in this series."
But for the time being, there is plenty to like, even if his solitary over, which cost 20 runs and included a backfoot no-ball, suggested that his second string (or perhaps third - he can also keep wicket) requires some work.
"He has put his hand up tonight for a spot in the World Cup," Ngidi said. "It's exciting to see. He's got a long career ahead of him but if this is how he's going to keep going, I see a bright future for him.
"I think other batters can see from him that if you want to play for this team, that's how you're going to have to go about it. That can only put us in a better position - I'm very excited about what's going to come in the future."
Matt Roller is an assistant editor at ESPNcricinfo. @mroller98