Carlos Alcaraz began his Vienna Open campaign with a straight-sets victory over Karen Khachanov on Tuesday, while Alexander Zverev saved four match points to overcome Martin Landaluce in a grueling encounter.
World No. 3 Alcaraz defeated the former world No. 8 from Russia 6-4, 7-6 (7-5) in their first-round meeting, advancing without dropping a set.
The seven-time Grand Slam champion added the ATP 500 tournament in the Austrian capital to his schedule at short notice. He had not competed in Vienna since 2021.
Alcaraz missed action from mid-April through the end of August because of a wrist injury and has struggled for consistency since returning to the tour. His most recent appearance ended in a third-round defeat at the Shanghai Masters in early October.
"I really enjoyed it, even though I had to run, had to fight, had to sweat a lot. We both played great shots, great points. I would say it was a great match to watch and I'm really happy about it," Alcaraz said.
Alcaraz had to dig deep against the 30-year-old power hitter, recovering from a breakdown to take the first set.
In a closely contested second set, Alcaraz prevailed in a tight tiebreak with a perfectly weighted drop shot to seal the match.
The 23-year-old will next face Georgian Nikoloz Basilashvili or Austrian Jurij Rodionov in the round of 16.
Zverev kept his hopes of securing the year-end No. 1 ranking alive with a 7-5, 3-6, 7-6 (13-11) victory over Landaluce.
"I was pushed to the absolute limit," Zverev said. "Credit to Landaluce, he played an amazing match."
Zverev is assured of finishing the season atop the rankings, but a victory in his next match against either Tallon Griekspoor or Brandon Nakashima would put him in position to claim the No. 1 spot from the injured Italian Jannik Sinner in the rankings update next Monday if he reaches the quarterfinals in Vienna.
Zverev broke the 20-year-old Spaniard's serve for a second time in the 12th game to take the opening set 7-5.
Landaluce responded by taking an early lead in the second set and serving out the set to force a decider.
The third set remained tight, with Zverev leading 6-5 before earning two match points on Landaluce's serve. The young Spaniard held firm to force a tiebreak.
Zverev dug in during a back-and-forth tiebreak, saving four match points before securing victory on his fifth match point when the world No. 67 sent a forehand wide. The encounter lasted 3 hours, 5 minutes.