From 2017 to 2019, the Spaniard was the only man to beat him at the French Open, with the Austrian reaching the final twice and beating Novak Djokovic twice at Roland Garros in that time.
Ahead of the 2020 edition of the tournament, few would have been surprised if he went on to win it, but three years on, the 29-year-old doing so would be one of the biggest shocks in the history of the sport.
He looked more likely than anyone to bring an end to the Big 3’s reign of dominance when he won the 2020 US Open, finally claiming his first Grand Slam after losing three finals, but he hasn’t been the same player since.
Triumphing in New York left him physically and mentally exhausted, and he took some time out to recharge in early 2021.
“It had something to do with the US Open title,” he said. “Chasing a goal for such a long time and then finally achieving it, it took a lot out of my body and my head.”
He returned to action at the start of the clay court season feeling rejuvenated, but disaster struck that spring when he picked up a serious wrist injury that would keep him out of action for nine months, causing him to drop from fourth to 339th in the rankings.
After hugely struggling initially on his long-awaited, often delayed return, he enjoyed an encouraging latter half of 2022 and climbed back into the top 100, but it proved to be something of a false dawn with him then losing eight of his first nine games of 2023, despite not facing many top opponents.
Given that, as this year’s clay season started, people weren’t talking about whether he could win the French Open. Instead, they were asking the question: Will he ever be able to compete for it - and other major titles - again?
He hasn’t been able to do so in the first two tournaments he’s played on his favourite surface, going out in the third round at the Estoril Open and in the second round at the Monte Carlo Masters.
That being said, there have been some encouraging signs for those longing for the real Dominic Thiem to finally reemerge.
Before a disappointing defeat to Quentin Halys in Portugal, he picked up back-to-back wins for the first time in seven months and the second of them, a 6-2, 6-2 victory over exciting talent Ben Shelton was very impressive.
Even more impressive than that were his two games in Monte Carlo, a comfortable win over Richard Gasquet and a defeat to Holger Rune.
He was a joy to watch against Gasquet, hitting 19 winners, some from the back of the court and some at the net.
One of the most positive aspects of his play was the power he was able to generate from his shots. That was one of his key strengths back in his heyday and something he’s been missing since his wrist issues began.
"Some positive signs happened already in Estoril and today,” he said after the match. “I had the feeling that I was doing from time to time good damage with both my forehand and backhand.
"The power wasn't there last year even when I started to win matches and played better… the power wasn't there yet. Also maybe not at the beginning of this year.
"In the last month, it's coming back, especially in practice. The shots are there, the power is there like before, but I was using it wrong. There's full trust again in the wrist and the forehand."
While he lost his next match in straight sets, there were some real signs of progress in that one too.
Rune, already number nine in the world at the age of 19, is one of the tour’s biggest talents in a long time, and Thiem was able to go toe to toe with him for the entirety of the second set, winning just three points less.
For the first time in a good while, he had the endurance to stay in rallies with one of the best players in the world and the shotmaking abilities to win them with some real touches of class.
If he can continue to perform at such a level going forward, he can be more than a match for the vast majority of players that he faces and could put together a strong run at Roland Garros if the draw is kind to him.
He’ll need to improve his game further if he wants to take the fight to the world’s best again, and whether he can do so is very much uncertain right now, but he does at least look to be on the right track.
