California - Roger Federer made quick work of Ivan Dodig on Monday, keeping his Indian Wells title defence on track with a 6-3, 6-1 third-round victory over the 60th-ranked Croatian.
Federer needed just 61 minutes to seal the victory - abetted somewhat by Dodig's six double-faults, the last of which came on match point.
The quick finish may have been a godsend for the Swiss great, who said he "tweaked" his back late in the match.
However, Federer said he fully expected to be fit enough to continue his pursuit of a first title of 2013.
"I'm not too worried," Federer said. "I have gone through it so many times where you feel a little tweak. You might play next day. Now this time around I have a day off, extra time.
"From that standpoint I'm not worried at all."
Leonardo Mayer's back injury was bad enough to have the Argentinian pulling out of his scheduled third-round match against Rafael Nadal, sending the fifth-seeded Spaniard into the round of 16 by walkover.
That meant Nadal had a chance to rest his troublesome left knee, but cost him more of the match experience he says he needs as he continues his comeback from a seven-month injury layoff.
The former world No 1, currently ranked fifth, returned in February, reaching one final and winning two titles in three clay-court tournaments in Latin America.
This is his first hard-court tournament since injury forced him out of the Miami Masters last March. Nadal remained on course for a possible quarter-final showdown with Federer. But first he faces a potentially tough fourth-round clash with red-hot Latvian Ernests Gulbis, who defeated 20th-seeded Italian Andreas Seppi 5-7, 6-3, 6-4.
Gulbis became the first qualifier to win a title this season in Delray Beach and he came through qualifying here as well. Including those qualifiers, he has won 13 competitive matches in 17 days.
The Latvian was looking forward to another crack at Nadal, who has beaten him in four prior encounters.
"I like to play against him," he said, noting that he has twice taken Nadal to three sets but each time suffered from his own lack of experience and lack of fitness.
"He just broke me down," Gulbis recalled.
"I think the way I play right now, that should make a difference," Gulbis said. "Of course he's a great player, but I believe - honestly I believe - that if I play my best game I can beat him."
Sixth-seeded Czech Tomas Berdych also advanced with ease, beating Germany's Florian Mayer 6-4, 6-1.
Berdych lined up a clash with 10th-seeded Frenchman Richard Gasquet, a 6-1, 6-4 winner over Poland's Jerzy Janowicz.
Victoria Azarenka, the top women's seed in this combined ATP Masters and WTA tournament, was trying to further her title defence on Monday night with a third-round match against Belgian Kirsten Flipkens.
Fourth-seeded German Angelique Kerber advanced on schedule, as did former US Open champion Samantha Stosur of Australia and former world No. 1 Caroline Wozniacki of Denmark.
Stosur, seeded seventh, beat China's Peng Shuai 6-3, 3-6, 6-2 while Wozniacki, a former Indian Wells winner, beat Russian Elena Vesnina 6-2, 6-1.
Results on Monday from the sixth day of the ATP Masters and WTA BNP Paribas Open (x denotes seeded player):
Kevin Anderson (RSA) bt Jarkko Nieminen (FIN) 6-3, 6-1
Rafael Nadal (ESP x5) bt Leonardo Mayer (ARG) walkover
Ernests Gulbis (LAT) bt Andreas Seppi (ITA x20) 5-7, 6-3, 6-4
Tomas Berdych (CZE x6) bt Florian Mayer (GER x27) 6-4, 6-1
Roger Federer (SUI x2) bt Ivan Dodig (CRO) 6-3, 6-1
Richard Gasquet (FRA x10) bt Jerzy Janowicz (POL x24) 6-1, 6-4
Gilles Simon (FRA x13) bt Benoit Paire (FRA) 3-6, 7-6 (7/5), 6-4
Stanislas Wawrinka (SUI x18) bt Lleyton Hewitt (AUS) 6-4, 7-5
Angelique Kerber (GER x4) bt Yanina Wickmayer (BEL x30) 6-1, 7-6 (7/4)
Garbine Muguruza (ESP) bt Magdalena Rybarikova (SVK) 6-4, 6-0
Nadia Petrova (RUS x10) bt Julia Goerges (GER x21) 6-1, 6-2
Samantha Stosur (AUS x7) bt Peng Shuai (CHN x32) 6-3, 3-6, 6-2
Caroline Wozniacki (DEN x8) bt Elena Vesnina (RUS x29) 6-2, 6-1
Mona Barthel (GER x24) bt Ana Ivanovic (SRB x11) 6-1, 3-6, 6-0
Victoria Azarenka (BLR x1) bt Kirsten Flipkens (BEL x28) 3-6, 6-3, 6-0
Urszula Radwanska (POL) bt Jamie Hampton (USA) 6-0, 7-6 (7/4)