Stefanos Tsitsipas began his Almaty Open campaign with a hard-fought victory over Aleksandar Kovacevic, winning 7-6(9), 3-6, 6-3 after more than two hours on court.
The Greek former world No. 3 faced a stern test from the American, with both players' one-handed backhands adding an interesting tactical element to the contest.
Tsitsipas was pushed to the limit in the opening-set tie-break, where he saved three set points before eventually taking the lead. Kovacevic responded by claiming the second set 6-3, but Tsitsipas regained control in the decider to secure his place in the second round.
After the match, Tsitsipas credited his persistence for helping him overcome the challenge and praised Kovacevic's serving and improvement.
The victory marked Tsitsipas' 35th win of the season, with 18 of those coming since his run in Gstaad in July.
He will next face Kazakh wildcard Mikhail Kukushkin, who is competing in the final tournament of his professional career before retirement. Tsitsipas leads their head-to-head record 4-0, giving him a strong historical advantage ahead of the encounter.
Fifth seed Karen Khachanov also progressed, defeating Japan's Rei Sakamoto 6-2, 6-4 in a convincing first-round performance.
Khachanov is among three former Almaty Open champions in this year's draw, alongside defending champion Daniil Medvedev and 2023 winner Adrian Mannarino. Their presence adds further experience to a competitive field in Kazakhstan.
Elsewhere, Sho Shimabukuro recovered from a set down to defeat Roman Safiullin and earn a second-round meeting with top seed Medvedev.
France's Terence Atmane also advanced after beating Rinky Hijikata, while Hungary's Fabian Marozsan defeated home favourite Timofey Skatov to set up a clash with third seed Alexander Bublik.
With Tsitsipas overcoming an early test and Khachanov progressing without dropping a set, the Almaty Open's opening round has produced several intriguing matchups as the seeded players begin their campaigns.
