Matthew Ebden’s impressive run at the Indian Wells Masters is over, with the Australian qualifier losing in the fourth round to big-serving American John Isner.

The 11th-seeded Isner beat Ebden 6-4 7-5 on Wednesday to reach the quarter-finals.

World No.1 Novak Djokovic is also through to the quarters after battling past Spaniard Pablo Andujar 6-0 6-7 (5-7) 6-2.

Djokovic entered the fourth-round match with a 12-1 record on the year, having already captured the fifth grand slam title of his career at the Australian Open.

“In the end, I was lucky to get through some points,” said Djokovic, who has won the past three grand slams. “I am happy to go through to the next round.”

Djokovic will next face Nicolas Almagro, who surprised seventh seeded Tomas Berdych 6-4 6-0.

Djokovic looked to be charging his way into the quarter-finals after taking the first set 6-0 in just 28 minutes.

But he quickly found himself in the middle of a dogfight in the second as unseeded Andujar started to get his serve cracking, taking the set in a tiebreaker to level at one each.

Djokovic fired four aces and saved eight of eight break-point chances in the two-hour, 16-minute match.

“It is a fourth-round match,” Djokovic said. “My opponent is really a quality player. He deserves to be at this stage of the tournament.”

Spaniard Andujar, who upset No.18 seed Florian Mayer to en route to the fourth round, finished with one ace and four double faults.