ROTTERDAM, Netherlands: Top seed Roger Federer won a fourth successive indoor title, and his 71st career crown, when he hammered Argentine Juan Martin del Potro 6-1, 6-4 to win his second Rotterdam Open on Sunday.

Federer had ended 2011 with a hat-trick of trophies in Basel, Paris and London before picking up this week where he left off in the Dutch city seven years ago where he won his first Rotterdam event.

"Even if I had a good indoor season last year, this is a great start. It was tough to come back and play Davis Cup and here, but I did it," he said.

"I also managed to stay positive after the Davis Cup loss, which was important for me. This court feels like home to me," added the 30-year-old, who was part of the Swiss team defeated 5-0 by the United States last weekend.

The victory took Federer's record against del Potro to 9-2, with the Swiss winning three of four in the series after losing the 2009 US Open final to the South American.

Federer, a 16-time Grand Slam winner, has now assured himself of a 12th consecutive year in which he has won at least one ATP title.

"It's incredible that it took me seven years to come back and defend my title, I hope the next time is not so long. But if it is, then it means I'll be playing for another seven years," joked Federer, who saved all seven break points he faced in a reassuring 88-minute victory.

Federer stormed into a 5-0 lead, with del Potro finally troubling his Swiss rival after 28 minutes when he rallied for 1-5.

But Federer maintained his red-hot form to sweep the set in 33 minutes.

Del Potro's resistance stiffened in the second, with Federer saving break points in the fourth, sixth and eighth games.

"I just tried to stay in the point and not make mistakes. I kept this mindset throughout the match and it really helped," said Federer.

"I may have won the first set easy, but of course I knew that the second would not be as easy. I had to fight but I fought well. I tried to move forward against him and change the angle, the rhythm and the speed of the shot."

Federer closed out the contest on his second match point.

"Juan Martin had a great week," said Federer. "He's playing great tennis. I hope to see you at the (November) World Tour Finals."

Federer's winning week ended a run of two straight singles losses -- the Australian Open semis to Rafael Nadal and a Davis Cup rubber against John Isner.

"I felt a bit tired early in the week, it's been a busy few weeks for me. I pushed myself to get better as the week went on. At the end I felt I was playing my best," said the world number three.

Federer will now head to his base in Dubai before playing at the ATP tournament there a week from Monday.