After four games and only 13 minutes of play, Alexander Zverev was through at the Shanghai Masters.

The third-seeded German advanced to the third round Wednesday after Aljaz Bedene retired from their match with a right knee injury while trailing 4-0.

Sixth-seeded Grigor Dimitrov also advanced, but had to save three match points before beating Ryan Harrison 3-6, 6-3, 7-6 (6).

“Those are the matches I really want to win,” Dimitrov said. “I was feeling good the whole match, even coming out of the first set, which he was playing well. I just had to find my way through the whole match.”

The 46th-ranked Harrison led 4-2 in the third set and then 6-3 in the tiebreaker. But Dimitrov won the final five points to get through.

“I just had to be there (on those match points),” Dimitrov said. “At (my) match point, I just had to make my first serve because I knew he would go for it if not.”