Roger Federer found himself in danger of a rare second successive defeat on Tuesday before recovering to beat Germany's Michael Berrer 6-1, 3-6, 6-3 in the opening round of the Swiss Indoors in Basel.

Following his surprise loss to David Nalbandian in last Sunday's Madrid Masters final, the world No. 1 had seemed back to his ferocious best as he ripped through the opening set.

Beginning the defense of his hometown title with two aces and two service winners, the Swiss dropped just three points on serve while twice breaking his left-handed opponent.

But Federer then found himself trailing 0-4 in the second set after a string of uncharacteristic errors combined with some bold strokes from the world No. 56.

Federer broke back in the next game but was unable to salvage the set.

Faced with the prospect of losing two successive tour matches for the first time since May 2003, the top seed was rescued when Berrer double-faulted at break point to fall 2-4 behind.

Federer still struggled to kill the match off and was taken to deuce at 5-3 before finally serving out with an ace and a service winner.

"It's almost laughable that I have to explain why I lost a set," Federer said in an on-court interview.

"The balls are quite a bit slower here than in Madrid but I'm sure I'll get used to it and play better in the second round."

Spanish third seed David Ferrer and Argentine seventh seed Juan Ignacio Chela, however, failed to join Federer in the second round.

Ferrer was upset 4-6, 6-7 (3) by Argentine world No. 51 Agustin Calleri while Chela was beaten 3-6, 4-6 by Austrian world No. 55 Stefan Koubek.

Yesterday, Argentina's Juan Martin Del Potro advanced after American Michael Russell retired at 5-2 while another Argentine Guillermo Canas, the sixth seed, eased into the second round with a 6-4, 6-3 victory over compatriot Jose Acasuso.

In Linz, Austria, Ai Sugiyama of Japan rallied to upset eighth-seeded home favorite Sybille Bammer 2-6, 7-6 (5), 6-0 on Tuesday in the first round of the Generali Ladies.

From 1-2 down, Bammer won seven straight games to win the first set and lead 2-0 in the second.

But the 21st-ranked Austrian did not score a point while serving for the match at 5-3. Bammer led 5-4 in the tiebreaker, but Sugiyama won the next three points to clinch it and didn't drop a game afterward.

Sixth-seeded Patty Schnyder advanced by beating Aravane Rezai of Hungary 6-4, 6-3.

Swiss Schnyder broke Rezai win the first set. She came back from an early break in the second to set up a second-round match with Australian Alicia Molik, who beat Agnieszka Radwanska of Poland 6-4, 3-6, 6-1.

Julia Vakulenko dropped a match point before ultimately defeating Russia's Maria Kirilenko 7-5, 6-7 (0), 6-4.

The Ukrainian, who also beat Kirilenko at this year's US Open, led 5-3 in the second set. But her Russian opponent won eight of the next 11 games to lead 4-2 in the decider before Vakulenko won the next four to close it out.

(Shanghai Daily via Agencies October 25, 2007)