Roger Federer takes on friend and doubles partner Stanislas Wawrinka for a place in the Indian Wells semi-finals.
Wawrinka has never been past the last eight at the BNP Paribas Open. If he's going to break that streak he will need to beat Federer for the first time on hard courts, a tough ask given his head-to-head record against his compatriot.
Federer has won seven of their eight matches and beat Wawrinka three times in 2010 before crushing him 6-1, 6-3, 6-3 at this stage of the Australian Open.
Federer has produced some solid tennis to reach this stage, seeing off Igor Andreev, Juan Ignacio Chela and Ryan Harrison without dropping a set. However he will need to raise his level for now on to keep the world number two ranking as he could face Novak Djokovic in the last four.
Wawrinka has had some fine results, producing a stunning comeback to see off Nikolay Davydenko and also hitting back from a set down to defeat Tomas Berdych.
Wawrinka's main problem in the past has been a lack of belief in the big matches and sometimes his first serve can go missing. However it will be fascinating if playing doubles with Federer will enable him to loosen up and come out swinging for this match.
