Rafael Nadal beaten by Dominic Thiem in Italian Open

The Austrian won 6-4 6-3 against the 14-time Grand Slam tournament winner in Rome for only his second victory in six meetings between the two

The Spaniard's unbeaten run on clay this year was ended by Dominic Thiem (Getty)

Rafael Nadal has been knocked out of the Italian Open after a straight-sets defeat by Austrian Dominic Thiem.

The quarter-final victory by Thiem avenged a defeat by the same opponent in last week's Madrid Open.

The Austrian won 6-4 6-3 against the 14-time Grand Slam tournament winner in Rome for only his second victory in six meetings between the two.

The defeat ended the 30-year-old Spaniard's unbeaten run on clay this year which had stretched to 17 matches.

Thiem reaches for a shot in the second set (Getty)

They had last met in the final in Madrid less than a week ago and that time it was the Spaniard who triumphed 7-6 (10/8) 6-4.

Nadal had also beaten Thiem in the final of the Barcelona Open but he went down to the 23-year-old in Italy.

Thiem's reward is a semi-final meeting with either Novak Djokovic or Juan Martin del Potro who were due to meet in the final quarter-final on Friday evening.

The other semi-final will see Germany's Alexander Zverev take on American John Isner.

Isner was a 7-6 (7/3) 2-6 7-6 (7/2) winner against Croatian Marin Cilic earlier on Friday and then Zverev defeated Canadian Milos Raonic 7-6 (7/4) 6-1.

PA