Dominic Thiem gives Rafael Nadal his first clay court loss of 2017

Entering Friday, Rafael Nadal was 17–0 this clay court season.

Entering Friday, Rafael Nadal had dropped just two sets during the 2017 clay court season. He was 17–0 on clay this year. It wasn't quite vintage King of Clay, but it was something close. 

Two of those victories were against Dominic Thiem. Nadal beat the 23-year-old Austrian 6–4, 6–1 in the Barcelona final, and followed that up by topping him 7–6(8), 6–4 in the final at Madrid. But on Friday, Thiem handed Nadal his first clay court setback of the year, conquering the Spaniard 6-4, 6–3 in the Rome quarterfinals. It was a dominant performance from Thiem, who overwhelmed Nadal with powerful groundstrokes—a rare sight on clay. 

THAT BACKHAND! 😳⚡️

@ThiemDomi #ibi17 pic.twitter.com/KBUtgPHUp3

— Tennis TV (@TennisTV) May 19, 2017

Nadal has started to regain his aura of clay-court invincibility this season, but Thiem's triumph isn't a big shock. Clay is his best surface—Thiem is defensively sound, and he's most comfortable at the baseline—and he showed marked improvement in Madrid after Nadal overwhelmed him in Monte Carlo. 

The French Open is looming, but the big question is which players will challenge Nadal. Novak Djokovic has been out of sync since his 2016 Roland Garros title, while Andy Murray's clay court season has been something of a debacle. Roger Federer wouldn't have been a favorite in Paris, but he's skipping Roland Garros. There's 2015 champion Stan Wawrinka, though he's had a clay season to forget. If Dominic Thiem goes on to win the Italian Open, he'll likely be considered Nadal's foremost adversary in Paris. 

Here is how he closed it out.....

@ThiemDomi 👏🎾#ibi17 pic.twitter.com/98EJmVQW0b

— Tennis TV (@TennisTV) May 19, 2017

We could very well see Thiem–Nadal IV at Roland Garros. The clay surface rivalry between the two will get a lot of hype over the coming weeks, and with good reason. Thiem's best Slam came in 2015, when he made the French Open semifinals, and he'll be a popular pick to make a deep run in Paris after his successful clay court season. But for the 30-year-old Nadal, a few days' extra rest before his favorite Slam might just be what the King of Clay needs ahead of his try for a record 10 French Open titles.