The Spanish world number one took his Roland Garros win-loss record to a jaw-dropping 86-2 as he captured his 17th Grand Slam title.
Thiem arrived in Paris in hot form, having picked up more Tour-level wins than any player in 2018 and beaten Nadal in the Madrid Open quarter-finals last month, snapping Nadal's 21-match winning streak and his run of 50 straight sets won on clay.
"It's unbelievable now, I can't describe my feelings", Nadal told the crowd on Philippe Chatrier Court moments after capturing his 17th Grand Slam trophy with a 6-4 6-3 6-2 victory.
In his on-court speech after Nadal's 6-4, 6-3, 6-2 victory, the 24-year-old Thiem said: "I still remember when you won here the first time, 2005".
2-nd player after Australia's Margaret Court to win a single Grand Slam title 11 times.
Thiem was still on the back foot in the third set, being forced to save four break points in the first game.
GETTY Rafael Nadal vs Dominic Thiem LIVE STREAM Dominic Thiem is chasing his maiden Grand Slam title
He displayed his lethal weapon of single-handed backhand, while being troubled by unfavorable performance on his first serves, conceding the first set 6-4.
The French Open final is free to watch on TV for viewers in the United Kingdom. The second set was rife with lost opportunities for the up-and-coming Austrian, who might one day claim a French Open title of his own - but quite possibly after Nadal has stepped away. Midway through the opening set, Nadal's aqua T-shirt was so soaked with sweat it stuck to him, so he changed into a fresh one at a changeover, drawing catcalls from spectators.
He still occasionally inconvenienced the reigning champion, not least when a deft drop shot brought up a point to break back at 2-4.
Thiem scrapped hard to save four break points but Nadal is relentless, keeping up the pressure until the seventh seed sends a backhand long.
Another feature was his ridiculously slow play when serving, nearly always over the 25-second limit and sometimes going well into the thirties. Nadal's "La Decima" was his 10th French Open, and he managed it without dropping a set throughout the tournament. He's won a record-setting 10 titles on the clay at Roland Garros and often finished off his final opponents in straight sets.
The women's doubles final is also Sunday.
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