The Spaniard has now won three straight titles, after his Barcelona Open and Monte Carlo Masters victories, while his record on clay this year is 15-0.

Nadal edged the Austrian in the tie-break of a tense first set that lasted one hour and 18 minutes.

He broke world number seven Thiem early in the second set to set up the win.

Nadal will be confirmed as the new world number four, replacing 18-time Grand Slam champion Roger Federer, when the new rankings come out on Monday.

That will improve his seeding for the French Open, which starts on 22 May and where Nadal is a nine-time champion.

Nadal, who beat defending champion Novak Djokovic in the semi-final, has now won his 30th ATP World Tour Masters 1000 title, tying the all-time record with Serbia's Djokovic.