In almost three hours and 15 minutes, Italian 10th seed Jannik Sinner outlasted Australian qualifier Thanasi Kokkinakis 6-7 (9), 6-4, 7-6 (6) on Tuesday in first-round action at the Western Southern Open in Mason, Ohio.

On his 21st birthday, Sinner recovered after losing a lengthy first-set tiebreak in which he saved three set points and led 9-8 before losing the final three points to Kokkinakis.

"In the beginning I was not playing so well or feeling the ball so well," Sinner said. "I tried to be a little bit more aggressive, which I had to do because Thanasi is a very attacking player. Let's take the positives out of this match, and hopefully in the next round I can play also at a higher level."

Sinner trailed 3-2 and 5-4 in the third-set tiebreak before pushing ahead and winning on his second match point.

Kokkinakis had a 13-6 advantage in aces and saved eight of 10 break points. But Sinner saved five of six break points, won 26 of 30 (86.7 percent) of points at the net and hit 43 winners overall.

Australian Nick Kyrgios, who returned to the proverbial winner's circle two weeks ago in Washington, D.C., opened his tournament with a 7-5, 6-4 win over Spain's Alejandro Davidovich Fokina. Kyrgios' lone ATP Masters 1000 final appearance came at this Cincinnati-area event in 2017.

"The conditions are a lot different here to (last week at) Montreal," Kyrgios said. "It's more lively, harder to hit the ball in, but I responded well and returned well today. Hopefully I can keep it going."

Americans fared well Tuesday. No. 11 seed Taylor Fritz beat Argentina's Sebastian Baez 6-1, 6-1 in just 54 minutes. Tommy Paul dispatched Jenson Brooksby 6-3, 6-2 in an all-American affair. And American wild card Ben Shelton took down Italian qualifier Lorenzo Sonego 7-6 (5), 3-6, 7-5.

Other winners Tuesday included Alex de Minaur of Australia, lucky loser Fabio Fognini of Italy, Miomir Kecmanovic of Serbia and Borna Coric of Croatia.

In second-round action, No. 3 seed Carlos Alcaraz of Spain toppled American wild card Mackenzie McDonald 6-3, 6-2.

The final first-round match still to be decided Tuesday night pitted Great Britain's Daniel Evans against Filip Krajinovic of Serbia, and several second-round matches were also scheduled for primetime.

Top seed Daniil Medvedev of Russia was slated to oppose Botic van de Zandschulp of the Netherlands; 13th seed Diego Schwartzman of Argentina will play Aslan Karatsev of Russia; and 14th seed Marin Cilic of Croatia will battle Finland's Emil Ruusuvuori.