The scoreboard didn't show it yet, but Novak Djokovic was already in trouble in his Cincinnati Open opener, even while leading by a set. From the second set on, he spent his time between points squatting and bending, desperately gasping for air in Ohio's notorious humidity. Eventually, Thiago Agustín Tirante of Argentina dispatched him 2-6, 6-4, 6-4, notching the biggest win of his career.

For over a decade, Djokovic has dominated tennis on any surface, but early exits at non-Slam events have become his new normal. The 39-year-old has long insisted that at his age, Grand Slams and the Olympics take priority, and his results reflect that. He reached the final at Roland Garros and the semi-finals at Wimbledon last month, but this was just his third non-Slam tournament of the season. He's failed to reach the quarter-finals in any of them, compiling a 2-3 record across Indian Wells, Rome, and Cincinnati.

Early on, Djokovic cruised through the first set, but the humidity got to him early in the second. He called for the physio and doctor while leading 6-2, 2-1, vomited into a towel, and had his blood pressure checked. He moved at half-speed for most of the match. "It was not an enjoyable match for me, for sure, the way I felt," Djokovic said. "Not the first, I guess, not the last time, but it is what it is."

While Djokovic crumbled, Tirante stayed strong. The 25-year-old Argentinian, one of the biggest servers on tour, used his serve and potent forehand to keep Djokovic behind the baseline and close out the win. Incredibly, the world No. 50 now holds a 4-1 record against top-10 opponents.

After the defeat, Djokovic walked straight to his media conference and explained his struggles: "It's just the condition that I have health-wise. It's been bothering me for the last couple of years. And a lot of issues, especially when it's humid and hot. Yeah." He admitted he'd anticipated a tough day but that nerves and pressure made it worse. Asked if he'd return to Cincinnati, he said, "I certainly hope so, but it looks more likely not, unfortunately. But let's see what the future brings."

Djokovic's preparation included a promotional tour for his upcoming Amazon Prime documentary, which took him to the US during the World Cup before the final stretch of the North American hard-court season. He'd decided to play Cincinnati to get matches before the US Open, but instead he'll again have to find his footing quickly in New York, where he's reached the semi-finals or better in six of his last seven Slams.

Elsewhere, Arthur Fery made a positive debut in the Cincinnati main draw, beating James Duckworth 6-4, 2-6, 7-6(4) in a tense three-setter. Fery took four weeks off after Wimbledon, so this was his first match since his semi-final run at the All England Club - a result that's changed his career trajectory. He'd never won a Masters 1000 main-draw match before, and this was his first direct appearance at one despite being seeded. It took a huge fight for the 32nd seed to get over the line, especially after falling behind in the final-set tiebreak at 4-3. But Fery responded brilliantly, hitting two deep returns to reach 5-4, then serving well to close it out.

Next up for Fery is fifth seed Alex de Minaur, who also struggled but came back from a set down to beat qualifier Quentin Halys 1-6, 6-3, 7-6(4).