Monte Carlo, Monaco ? Roger Federer seems no closer to figuring out how to beat Rafael Nadal on clay.

The top-ranked Swiss star lost his fifth-straight match to Nadal on clay Sunday at the Monte Carlo Masters, 6-4, 6-4, and the second-ranked Spaniard extended his winning streak on the surface to 67 matches.

“I lost four times against Rafa,” Federer said. “I’d rather have that than lose against four different guys.”

Nadal won the title at Monte Carlo for the third straight year. The two-time defending French Open champion is 14-0 in clay-court finals and 4-0 against Federer.

But despite his latest setback, the 10-time Grand Slam champion believes he’s still on the right track to win the only major that eludes him.

Federer has four Wimbledon titles, and three at both the U.S. and Australian opens, but still needs the French Open to complete the sweep.

“I feel this match gave me some information,” Federer said. “I’m absolutely in the mix with him on clay. I feel like I’m in good shape for the rest of clay-court season, and it’s going to come down to the French Open to see who wins.”

Nadal beat Federer on clay last year in the finals of the Monte Carlo Masters, the Rome Masters and the French Open. He also beat Federer in the 2005 Monte Carlo semifinals.

Only at the Rome Masters did Nadal have to save a match point against Federer on clay.

“Today’s match was very close. For sure, it’s a surprise to win in two sets against the No. 1,” Nadal said. “I was confident because I was playing my best tennis this week.”

Nadal is the first player to win three straight Monte Carlo titles since Ilie Nastase (1971-73), and only the fourth in the Open era to have won it three times. Bjorn Borg and Thomas Muster also were three-time winners.

Federer, who won his previous two meetings with Nadal on other surfaces, missed two chances to break Nadal in the eighth game of the first set.