Thiem appeared likely to face an uphill battle at the Foro Italico, with Nadal having won his last 17 clay court matches, winning three titles in the process.

The 23-year-old, who was beaten by Nadal in the Barcelona and Madrid Open finals, would produce a strong display to dominate the match.

He would claim the opening set 6-4 and maintained the momentum to take the second 6-3, wrapping up a straight sets win.

Victory over nine-time French Open winner Nadal will see Thiem emerge as a genuine contender for the Grand Slam tournament.

He will have another chance to test his credentials when he takes on either Argentina’s Juan Martin Del Potro or Serbia’s Novak Djokovic in the semi-finals.

Djokovic impressed to win the first set of their clash, but the world number two will be forced to resume play tomorrow at 2-1 down in the second, after rain halted play.

Germany’s Alexander Zverev continued his impressive form, with the 20-year-old beating Canada’s Milos Raonic 7-6, 6-1.

He will now face John Isner in the semi-finals, with the American having beaten Croatia's Marin Cilic 7-6, 2-6, 7-6.

In the women’s competition, reigning French Open champion Garbiñe Muguruza, continued her preparations for her title defence by reaching the semi-finals in Italy.

The Spaniard won 6-2, 3-6, 6-2 against the United States’ Venus Williams.

Elina Svitolina of Ukraine will face Muguruza in the last four, having beaten second seed Karolina Pliskova of the Czech Republic 6-2, 7-6.

Romania's Simona Halep won 6-2, 6-4 against Estonia’s Anett Kontaveit in her quarter-final and will now play Kiki Bertens, after the Dutch player beat Australia’s Daria Gavrilova 6-3, 6-3.

The competition is an ATP World Tour Masters 1,000 event, as well as a Premier 5 event on the Women's Tennis Association tour.

It is a key preparation event for the French Open, the clay court Grand Slam, due to begin on May 28 at Roland Garros in Paris.