Stefanos Tsitsipas survived a big scare in his "crazy battle" with Jack Sock to reach the third round of the Indian Wells Masters.

The fifth seed was taken all the way to a third-set tie-break by Sock, which he trailed 5-3 before recovering to claim a 7-6 (7-5) 3-6 7-6 (7-5) victory in a gripping contest.

Sock, ranked 140 places below his opponent, put his strong forehand to good use to hold in a first set that went the distance but was undone by some unforced errors.

After responding brilliantly by taking the second set, after once again holding his serve, the American looked to be heading for defeat when 40-0 down at 5-6 in the third set.

However, he dug deep to force another tie-break and was within two points of a big victory, only for two more unforced errors to cost him a place in the last 32.

"It was a crazy battle; we both left everything out there," Tsitsipas said. "Jack played incredibly well at times but I was able to bring out the best in my game at the end. 

"I proved I could play aggressive tennis and stay calm at the same time."

Tsitsipas will now face another home hopeful in Jenson Brooksby, who saw off Karen Khachanov 6-0 6-3 earlier in the day.

Jannik Sinner battled to a 6-3 6-3 win over Laslo Djere elsewhere in Saturday's action, while Denis Shapovalov and defending champion Cameron Norrie also advanced.

Fabio Fognini withdrew from his meeting with Nikoloz Basilashvili, who now awaits Norrie in the next round.