STUTTGART, Germany (AP) _ Rafael Nadal dropped serve three times and had to sweep five straight games to win the Mercedes Cup with a 6-4, 7-5 win over Stanislas Wawrinka of Switzerland on Sunday.

The top-seeded Spaniard hadn't previously dropped serve in the tournament, but had to rally from 5-2 down in the second set to claim his sixth title this year and his 93rd win in 94 matches on clay.

``I had a little luck, but I'm very happy I played well here,'' Nadal said. ``After losing the Wimbledon final to (Roger) Federer, it was hard to have a good tournament.''

Nadal is 23-5 in career finals, the highest winning percentage in the Open era.

The 50th-ranked Wawrinka had only won one match in eight attempts heading into the tournament after returning in May from a knee injury.

``I had almost no self-confidence before coming into this tournament,'' Wawrinka said. ``I'm just enjoying it at the moment. I played a really good match against the best clay-court player in the world.''

Wawrinka said he received a text message from Federer, who beat Nadal at Hamburg on May 20 for the Spaniard's only loss on clay in his streak.

``He ... didn't give me any advice about how to beat Nadal,'' Wawrinka said.