Rafa Nadal and Roger Federer stayed on track for a mouth-watering quarter-final showdown at the BNP Paribas Open after they both advanced to the last 16.

Nadal, twice champion at Indian Wells, was gifted his spot when Leonardo Mayer withdrew with a back injury before the start of their third-round match.

Federer, a four-times winner of the ATP Masters 1000 event, had minor back problems of his own but progressed with a commanding 6-3 6-1 victory over Ivan Dodig in a contest lasting 61 minutes.

Federer and Nadal last met a year ago, also at Indian Wells, when the Swiss won a semi-final battle 6-3 6-4.

Federer tweaked his back during the latter stages of his match against Dodig, but with a rest day to enjoy he was not worried that it could affect his last 16 match today.

“It’s not the first time it’s happened in my career, so, I know how to deal with it,” said the world number two.

Federer will next meet compatriot Stanislas Wawrinka, who beat Australian veteran Lleyton Hewitt 6-4 7-5 in an evening match at the Indian Wells Tennis Garden.

“I’m walking fine, I have a day off tomorrow. Everything is all right,” added Federer.

“It’s happened during grand slams, during tournaments, in practice.

“It’s just something you learn to deal with. And as long as I keep on playing, it’s all right. I also know I have a longer break to recover so, from that standpoint, I’m not worried at all.”

World number five Nadal, who is competing in his first tournament on a hardcourt surface in almost a year, was saddened when he learned that Mayer had withdrawn.

“That’s bad news, for sure, for the fans and for Mayer, especially,” said the Spaniard, who will next face Ernests Gulbis.

“I talked with him. It seemed like it’s nothing very, very bad.”

Meanwhile, Australian Open champion Victoria Azarenka struggled to find her rhythm against Kirsten Flipkens in the third round but finished strong to beat the Belgian 3-6 6-3 6-0.

Angelique Kerber also ad-vanced, heeding the advice of her coach to come from 1-4 down in the final set to beat Belgian Yanina Wickmayer 6-1 7-6.