Novak Djokovic and Rafael Nadal set up a blockbuster semi-final at the BNP Paribas Open with straight-sets wins on Friday.
World number one Djokovic was pushed before edging past Jo-Wilfried Tsonga in two tie-breaks at Indian Wells.
Surprisingly, Nadal was more comfortable, the Spanish fourth seed brushing past Kei Nishikori at the ATP 1000 event.
Nadal in particular has battled to reach the last four, and the huge task of Djokovic awaits him in what will be their 48th meeting.
Djokovic survived a tough contest against Tsonga, securing a 7-6 (7-2) 7-6 (7-2) victory over the Frenchman.
The Serbian went up a break in the first set and failed to capitalise before falling behind in the second but coming back.
Tsonga saved two match points in the 10th game with a pair of incredible shots, but was punished in the tie-break.
Nadal found his quarter-final far more straightforward, beating Japanese fifth seed Nishikori 6-4 6-3 in one hour, 33 minutes.
The Spaniard had won seven of his previous eight meetings with Nishikori and improved that record with his last victory.
CHANCES TAKEN, TSONGA'S SERVE COSTLY
Nadal won fewer return points (27-25) than Nishikori, but was able to take his chances.
Nishikori converted just two of eight break points, while Nadal capitalised on four of his seven in a clinical display.
Tsonga served at just 47 per cent against Djokovic, and that was never likely to be enough against the 11-time grand-slam champion.
Djokovic provided one of the finer moments of sportsmanship, telling the chair umpire he had touched a Tsonga shot which had gone out.
"To be able to be where I am today, in the semi-finals, and especially with the victory of today against a top, top player, that's something very important for my confidence," a happy Nadal said.
"It's very important to believe in myself too, and winning the way that I did."
Nadal added: "I know Novak is playing unbelievable, so it's difficult."
Saturday is semi-final day for the men and Djokovic against Nadal for a 48th time will take centre stage at Indian Wells. David Goffin and Milos Raonic do battle earlier in the day as they also bid to reach the final.