DELRAY BEACH, Fla. -- Third-seeded Alexandr Dolgopolov of the Ukraine won just his second match of the ATP season with a 7-6 (7-4), 6-3 victory over Russian Teymuraz Gabashvili in the first round of the Delray Beach Open on Monday.
He was joined in the second round by wild card Denis Kudla, a 22-year-old resident of nearby Boca Raton, who beat Lukas Lacko of Slovakia 6-3, 6-4.
Dolgopolov, who went 14-4 during a spring swing last year that included wins over then-No. 1 Rafael Nadal and Australian Open champ Stan Wawrinka, has struggled since undergoing knee surgery in May. He had lost his previous three matches, including a first-rounder in Memphis last week.
"I know I'm defending like 1,000 points," joked 26-year-old Dolgopolov, ranked No. 24 in the world. "I need points and for that I need wins."
Dolgopolov had a scare during the Australian Open in January when he felt knee pain and his surgeon suggested he take two months off to recover.
"I literally saw nine (different) doctors in three days, sent my MRI to Europe, and they all said I could play. But I didn't practice for three days and I wasn't in the best frame of mind."
Despite an admittedly nervous start against Gabashvili, Dolgopolov gained confidence as the match went on. He had nine aces, including one on match point.
Kudla also had some self-doubt before ousting Lacko. He double-faulted on game points three times, including while serving for the match, though he ultimately held serve each time.
"I was on fire and then I got a little tight," said the 22-year-old who is ranked No. 132.
Ivo Karlovic, who lost to Dustin Brown in two previous meetings last year, beat the 30-year-old in a night match 6-3, 6-7 (3), 6-2.
The fourth-seeded Karlovic, who has a towering serve that led to 23 aces, double-faulted to drop the second set. It was the fourth career tiebreaker he had lost to Brown. But the 35-year-old, the oldest player in the draw, rebounded by breaking Brown in the fifth game of the third set when Brown double-faulted then didn't drop another game.
Karlovic lost to Brown in Doha last year, despite being up a set and holding four match points in the second-set tiebreaker. Earlier this year he reached the semifinals in Doha before losing to David Ferrer.
With qualifiers Yoshihito Nishioka of Japan and Thanasi Kokkinakis of Australian and wild cards Andrey Rublev from Russia and American Stefan Koslov all younger than 20, the Delray Beach Open represents the first time since Brisbane in January 2012 that four teenagers are in an ATP main draw.