For many scrambling to watch highlights, it was the first time they took notice of the blonde-haired Thornton who hits the pitch hard and attacks the stumps at pace.
"I try to hit over 140kmph consistently. While you may go for runs, you are a chance to take wickets and go through a team," Thornton, who wears No. 58 in homage to Lee, said.
"Speed is king. I've always believed in that. Bowling fast is what sets me apart from others."
While his performances have naturally dipped from that high point, Thornton was the BBL's second-highest wicket-taker at mid-season.
It was the heights expected from Thornton many years ago when he made a rapid rise through junior ranks and represented Australia at Under-19 level.
At just 20, he made his BBL debut for Sydney Sixers against Brisbane Heat and dismissed Jimmy Peirson for his first wicket but leaked 40 runs and never played for them again.
"I was really young and got thrown into it. I didn't think I was ready at the time," Thornton reflected on his BBL debut.
But his obvious raw talent saw him earn a contract with NSW although he was stymied by back injuries and eventually delisted after the 2018-19 domestic season.
"I felt like I just needed an opportunity and wasn't getting it," Thornton said. "I always believed in my ability and believed I was good enough but I wasn't in the system. I was close to pulling the pin".
Instead of quitting altogether, Thornton plugged away in Sydney grade cricket before deciding he needed a change of scenery to rejuvenate his career.
So he ventured south to Melbourne, where he joined the famous St Kilda cricket club - a renowned breeding ground for Victorian state cricketers.
"There were expectations in his own mind where he wanted to be. He self-reflected and made a move to Melbourne. He is going into the golden years of his career and we see him as potentially a long-term player."
Jason Gillespie on Henry Thornton
He was mentored by veteran quick Simon O'Brien, particularly on how to better execute under pressure. While captain Adam Crosthwaite, a stalwart for Victoria in the 2000s, taught him the intricacies of setting fields.
It manifested in a spectacular premier club season in 2020-21, where he took 36 wickets at 14.42. "I probably needed to be let go by NSW, it was the best thing that happened to me," Thornton said. "I had to pick myself off the canvas and learn the craft."
But his starring turn for St Kilda failed to stir BBL interest with Thornton overlooked by every team ahead of the 2021-22 season.
"There are a lot of players in premier or grade cricket who should have an opportunity but they're missed and fall through the cracks," he said. "Just because you're not part of a system doesn't mean you're not good enough."
While on holiday in Sorrento, a picturesque coastal town in Victoria, over the festive season in late 2021, Thornton received a phone call out of the blue from Strikers boss Tim Nielsen who was scouring for a replacement fast bowler.
"I knew it was a massive opportunity," he said. "I thought if I could play one game and bowl fast I would be so happy with that. I had only been asking for an opportunity."
Five years after his sole BBL game, Thornton felt prepared and equipped to hold his own out in the middle. His confidence was justified when Thornton cemented a regular spot to be a key part of Strikers' late season revival with 13 wickets at 15.92 from seven matches.
Thornton became a strike weapon in Strikers' strong attack and was often deployed in the powerplay or when a wicket was needed. His growing stature was underlined when Thornton was backed to bowl at the death during Strikers' agonising last ball defeat against Sixers with a grand final spot up for grabs.
"When the season ended I sat down with my partner and couldn't believe what had happened. It was a blur," he said. "I felt in a better place with my skills than when I debuted. I'm not the finished product but I felt more comfortable."
Thornton's momentum continued when he was named Victoria's Marsh Cup 50-over player of the season. Perhaps surprisingly, he was overlooked for a state contract with Victoria but his disappointment was short-lived after South Australia's hierarchy once again came calling.
"To get delisted and come back...it's something that I didn't think would happen," Thornton said. "It [South Australia's contract] was reward for a lot of hard work. It's been a long journey."
South Australia/Strikers head coach Jason Gillespie had never seen Thornton bowl live before last season's BBL, but was left impressed with his ability to fight through adversity and saw parallels with his own injury-riddled career.
"I knew he had ups and downs after a rapid rise," Gillespie told ESPNcricinfo. "I know what it's like because when you're young you want everything.
"There were expectations in his own mind where he wanted to be. He had to adjust those thoughts and let his body heal. He self-reflected and made a move to Melbourne. He is going into the golden years of his career and we see him as potentially a long-term player."
Thornton has benefited from Gillespie's transparent ethos. "The advice has been simple: be super clear with what you want to do and communicate that to the captain," Thornton said. "My plans are super simple - bowl as quick as I can and try to hit the stumps. That's my role in the team. It's about playing with freedom and having belief."
While the focus is firmly on the BBL, Thornton is hopeful of making a first-class debut at some stage after being in the selection frame for South Australia during the first half of the Sheffield Shield season.
"A guy who can bowl 145kmph can be a massive asset, we've seen how devastating he can be," Gillespie said. "He'll need to work on his variations so he can be an all conditions, all surfaces type of bowler.
"We're conscious of not overcooking him. We've got nine seamers on staff at South Australia, but he's in the conversation [for their Shield team] constantly."
All of that's ahead but, whatever happens, Thornton will always have his magical 26th birthday to saviour.
"I don't think that will be repeated in my career. Something I will look back on at the end of my career and enjoy," he said. "It's been a crazy 12 months. I am just trying to play every game like it's my last."