Stefanos Tsitsipas overcame an upset stomach to beat Roberto Carballes Baena 4-6 6-3 6-3 in the first round of the Paris Masters and stay in contention for a spot at the season-ending ATP finals.

Tsitsipas has reached the Paris semifinals in the last two years and needs another deep run to have a chance of qualifying for the ATP finals tournament for the top eight players in Turin next month.

But he said his stomach problem created a “second battle” in addition to his opponent on Monday.

“I couldn’t even pump myself up at the beginning of the match, because when something is bothering you that much, it takes your entire concentration and focus,” Tsitsipas said. American Tommy Paul’s hopes of qualifying for Turin ended with a 6-3 7-5 loss to French veteran Adrian Mannarino.

Earlier, local favourite Hugo Humbert needed more than two hours to beat the 35th-ranked Brandon Nakashima 6-3 4-6 6-4.

Humbert, who saved two break points in the decider, extended his unbeaten record against Nakashima to 3-0. He will next take on another American player, Marcos Giron, who defeated Shang Juncheng 7-6(6) 7-6(6).

Dutchman Tallon Griekspoor also advanced with a 6-3 6-4 win over Luciano Darderi - setting up a second-round meeting with third-seeded Alexander Zverev - and Tomas Martin Etcheverry of Argentina beat Zhang Zhizhen 6-3 7-6(6). Etcheverry will next face Grigor Dimitrov.

Among those progressing Monday were also Francisco Cerundolo of Argentina, Arthur Rinderknech of France and Australian Jordan Thompson.

Defending champion Novak Djokovic is skipping the tournament this year. Jannik Sinner, who is guaranteed to finish the year at the No. 1 spot in the ATP rankings, is the top-seeded player in Paris.

Sinner, Carlos Alcaraz, Zverev and Daniil Medvedev have already secured their spot at the ATP finals from November 10-17.