MADRID, May 11 (Xinhua) -- World No. 1 and top seed, Rafael Nadal was knocked out of the Mutua Madrid open on Friday following a 7-5, 6-3 defeat to the 5th seed, Dominic Thiem.

The defeat ended a spectacular winning run from Nadal, who had won the last 51 sets he had played on his favorite red-clay surface.

The Spaniard had said prior to his defeat that Thiem was the toughest rival he could have faced on the surface.

"I'm not super happy when I win and I am not super sad now I have lost," he said, even though the defeat means Roger Federer, who isn't playing in Madrid, recovers the world number one spot.

Elsewhere Kevin Anderson beat Croatian qualifier Dusan Lajovic 7-6(3), 3-6, 6-3 to qualify for the semifinals.

In the women's tournament, unseeded Kiki Bertins continued her excellent week as she reached the final with a 6-2, 6-2 win over France's Caroline Garcia.