Casper Ruud, seeking his sixth ATP Tour championship of the year, rallied to reach the fourth round of the BNP Paribas Open in Indian Wells, Calif., on Monday.

The sixth-seeded Norwegian defeated 26th-seeded Lloyd Harris of South Africa 6-7 (4), 6-4, 6-4.

Ruud, 22, won his first career ATP title last year in a clay-court event at Buenos Aires. He added four more clay-court championships before prevailing earlier this month in hard-court event at San Diego.

He is riding a nine-match overall winning streak since a second-round loss to the Netherlands' Botic van de Zandschulp at the U.S. Open.

Ruud won Monday despite Harris racking up an 18-2 edge in aces. The key was Ruud saving all eight break points he faced on his serve.

"It was a very tough match and I was fortunate to get through in the end," Ruud said. "There were only some points here and there that decided this match. I saved a lot of break points and in crucial points I stepped up my game.

"It was frustrating because Lloyd was playing well and I was not really feeling the groove like I felt in the first match, and in the end I was fortunate to get through."

Eleventh-seeded Diego Schwartzman of Argentina joined Ruud in advancing with a three-set win. Meanwhile, 19th-seeded Aslan Karatsev of Russia and 23th-seeded Grigor Dimitrov of Bulgaria moved on in straight sets.

Schwartzman ousted Great Britain's Daniel Evans 5-7, 6-4, 6-0. Karatsev upset ninth-seeded Denis Shapovalov 7-5, 6-2, and Dimitrov got past 16th-seeded Reilly Opelka of the United States 6-3, 6-4.

Schwartzman lost just eight points in his final set.

Karatsev had no aces to Shapovalov's 12 and posted a miserable first-serve rate (44 percent), but he faced only one break point, which he saved.

Dimitrov put 77 percent of his first serves in play and won 86 percent of those points (32 of 37). He never faced a break point.