Indian Wells - Serbian lucky loser Miomir Kecmanovic reached the Indian Wells quarter-finals Wednesday when Japan's Yoshihito Nishioka retired with injury after dropping the first set of their last-16 clash.

Kecmanovic, who gained entry straight into the second round when fifth-seeded Kevin Anderson withdrew with an elbow injury, is the first lucky loser to reach the last eight since the ATP's Masters 1000 series began in 1990.

He had won the first set 6-4 when Nishioka, who received treatment on his back in a bid to carry on, called a halt.

The victory over 74th-ranked Nishioka will see 130th-ranked Kecmanovic break into the top 100 -- moving him a step closer to achieving his pre-season goal of finishing the year in the top 100.

The 19-year-old, who toppled 30th-seeded compatriot Laslo Djere in the third round, is reaping the rewards of a training stint in Tenerife with Austrian Dominic Thiem, Jan-Lennard Struff and Ernests Gulbis that he says opened his eyes to the quality of work needed to contend on the ATP Tour.

"A lot more intense," he said of the experience, compared to his usual off-season training.

"I didn't know that's what they were going for. That definitely opened my eyes to see how much more I have to work to get where I want to be."

In the quarters, he could face training partner Struff, who upset third-seeded German Alexander Zverev in the third round to set up a meeting with 13th-seeded Canadian Milos Raonic.