The Austrian, who was beaten by Nadal in straight sets in last year's championship match, pushed his illustrious opponent all the way in the first two sets, only to run out of steam. That development brought fans to their feet in Court Philippe Chatrier, roaring and clapping and, above all, wondering: Was this, now, a real contest? The answers arrived swiftly.
The Spaniard, Rafael Nadal began his expedition to collect Roland-Garros titles in 2005 by defeating Roger Federer in the semi-finals and 14 years later he does the same lift his 12th title in Paris and increases the Grand Slam tally by one in the Big Three's account and extends their count to 53. He won just two matches combined at Wimbledon in 2012, '13 and '15 - sandwiched around a fourth-round appearance in 2014 - and then missed the tournament altogether in 2016. Just the numbers are insane.
No one in tennis ever has won any major tournament that frequently.
"I know I played a great event a year ago", Nadal said in Paris on Sunday.
As much as Roger Federer and Rafael Nadal have shared the defining sporting rivalry of the last 15 years, until Sunday they had never actually been that close according to the metric most often used to judge tennis greatness.
Nadal, however, did not want to entertain any discussion of a pursuit of Federer. "I have been able to be very close to win another title there".
"You can't be frustrated all the time because the neighbor has a bigger house than you, or a bigger TV or a better garden". "Being honest, I am not very anxious about this stuff, no?" I feel very lucky about all the things that are happening to me.
So, of course, does Nadal.
Nadal has suffered more injuries throughout his career than Federer and that the world number one, Serbian Novak Djokovic, who is third in the list of great champions of all time with 15.
"Mentally, I lost a little energy because I had too many problems in a row", he said.
"When you are constantly hit in the face", he said in Spanish, "you end up being hurt".
The win was also Nadal's 82nd of his career and 59th on clay. Rafa has more titles to win. This took even more confidence from the Swiss' game, suffering the second straight break in game nine to lose the opener 6-3 after a forehand victor from Rafa who saved all ten break points he had to play against!
After watching Nadal for the past two weeks, seven-time Grand Slam champion Mats Wilander believes the Spaniard is still improving his game.
The 32-year-old Nadal claimed his crown after a match lasting 3 hours 1 minute that didn't go all his own way.
As a result, Thiem was playing for the fourth successive day in the final. Thiem clenched his fist.
Nadal was mighty relieved, opening the second set with a much-needed comfortable hold, firing a crosscourt forehand victor and delivering another one in game three to stay in front.
Nadal won 25 of 26 points on his serve before he was broken to cede the second set.
"It's a dream to win again, an incredible momentum", said Nadal.
But then Thiem wilted, and Nadal barged through the opening.
This time, it was Nadal who was filled with real worry. All Thiem could do was watch - and offer an appreciative thumbs-up.
"The beginning was unbelievable intensity of the match", said Thiem.