MADRID: Roger Federer believes avoiding Rafael Nadal at the Madrid Masters this week could prove crucial in his campaign to finally topple the king of clay and capture an elusive French Open title.

The Swiss second seed has yet to meet his Spanish rival on clay so far in 2009, but the two will be seeded for what would be a fourth straight final between the pair at Roland Garros in a month's time.

"It might have been a little bit of an advantage for Rafa to have beaten me before Paris on clay in the past seasons," said Federer prior to his start in Madrid.

"That gives him confidence and might have made it a little easier to beat me in the (last three Paris) finals.

"This year I haven't played him on clay but I'm hoping to play him here in the final. But even if it doesn't (happen) it could still be a good thing. It's different when you've played a month earlier and got to Paris knowing that you've beaten someone."

Federer, the holder of 13 Grand Slam titles, still needs a French Open trophy to complete his collection.

However, Nadal has proved a formidable obstacle winning the last four titles in Paris where he has never lost.

On court in the opening round of this combined 7.2-million-euro ATP and WTA event, women's number four seed Jelena Jankovic advanced easily over Nuria Llagostera Vives of Spain 6-2, 6-1.

However, other seeds slumped.

Australia's Samantha Stosur, who lost her only European clay match of the season in Rome last week, knocked out Polish tenth seed Agnieszwa Radwanska 7-6 (7-4), 6-1.

Russia's Elena Vesnina upended French number 13 Alize Cornet 7-5, 6-1 while Hungarian Agnes Szavay beat Italian Flavia Pennetta, seeded 12th, 6-3, 6-7 (2/7), 6-2.

Unfancied Czech Lucie Safarova advanced as Estonia's 16th seed Kaia Kanepi quit trailing 6-2, 2-3.

Meanwhile, Federer had no hesitation in endorsing Nadal's opposition to a failed attempt by Madrid organisers to change the colour of their match courts here to blue.

The ATP vetoed the attempt and Federer blamed the event for failing to follow procedure.

"You (should) go to the ATP and to the board in the normal way," said the Swiss still looking for his first title of the season. "You don't ask individual players.

"That is only dividing us, it should anyway be a unanimous decision.

"I don't think there a chance for blue clay," said Federer, who only got a brief glimpse at one remaining blue practice court at the Magic Box complex.

"We are against it, red clay is the tradition," he said in echo of Nadal's thought the day before.

Serena Williams also joined the crusade.

"We don't want to play on blue clay. I'm totally against it, 100 percent against blue clay," said the American.