California - Roger Federer's 6-3, 6-1 third-round victory over Ivan Dodig at Indian Wells on Monday was hardly back-breaking labor, but it did leave him seeking treatment for a sore back.
The Swiss great, whose triumph here last year gave him a fourth Indian Wells crown, needed just 61 minutes to get past the 60th-ranked Croatian.
Dodig made the Swiss great's task a bit easier with a bevy of untimely double-faults, the sixth on match point to bring proceedings to a close.
Despite spending so little time on the court, 31-year-old Federer admitted he was feeling some discomfort in his back at the end of the match.
"At the end I tweaked it a little bit," he said. "But it's not the first time it's happened in my career, so, I know how to deal with it."
He said he didn't expect it to hinder him in his quest for a first trophy in 2013, after he was denied title repeats in Rotterdam and Dubai.
"I'm walking fine," said Federer, seeded second in the first ATP Masters event of the year behind world No. 1 Novak Djokovic. "I have a day off tomorrow. Everything is all right."
Federer, owner of a record 17 Grand Slam singles titles, said such minor physical problems are nothing new.
"It's happened during Grand Slams, during tournaments, in practice. It's just something you learn to deal with," said Federer, who next faces fellow Swiss Stanislas Wawrinka, the 18th seed, who beat Aussie veteran Lleyton Hewitt.
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)