Nick Kyrgios has beaten world number one Daniil Medvedev at the Montreal Masters, while compatriot Ajla Tomljanovic has gone down 6-1, 6-2 to the woman atop the WTA rankings, Iga Świątek.
Coming off a title in Washington after his long run to the Wimbledon final, Kyrgios looked drained at various times throughout the match, but mustered a late surge to beat the Russian 6-7(2/7), 6-4, 6-2.
After scores were level at 2-2 in the third set, Kyrgios broke in the fifth game for a 3-2 lead.
The Australian won 14 of the final 16 points of the match as he raced to the finish line, with Medvedev pacing off court almost as quickly.
It was a remarkable finish considering how tired he looked, particularly early in the third set.
Kyrgios pulled out of the singles at the ATP tournament in Atlanta between Wimbledon and Washington, but he did end up playing the doubles, ultimately playing four matches and winning the final alongside Thanasi Kokkinakis.
Despite showing some signs of fatigue against Medvedev in Toronto, he said his body and mind were feeling good during the US hardcourt swing.
Although Kyrgios acknowledged form in best-of-three matches would not necessarily equal success at the best-of-five US Open, which starts on August 29.
"A grand slam is much, much different to any other tournament," he said.
"If I was to put myself in a position of a grand slam, you've still got to win another set against him and that's not easy at all. He's a machine and he's the best player in the world for a reason. A grand slam is a totally different beast.
"I feel confident in my body and my mentality going into the US Open but there's so much time between then and now.
"I've got to focus on this event and then Cincinnati. I'm not even gonna think about the US Open right now; I need to take care of my body."
While Kyrgios is enjoying career-best form coming off his first major final, it means a long time away from his family in Canberra.
The 27-year-old's mother is in hospital, prompting Kyrgios to write "Be strong Ma" when he signed the camera lens after beating Medvedev.
"It's hard because my mum is in hospital at the moment, my dad hasn't been very well, my brother just had a baby and I don't get to be there with my family when normal people would like to be with them," Kyrgios said.
"It's hard being from Australia because we can't travel back and forth.
"There's a lot of things people don't see. They only see me winning, losing, throwing a racquet, doing those things. They don't really understand the challenges that I face or what people on tour face, what's going on in their personal lives."
He will next face countryman Alex de Minaur, who beat Bulgaria's Grigor Dimitrov 7-6(7/4), 7-5 in their second-round clash.
Tomljanovic easily handled by Świątek
On the WTA side of the tournament in Toronto, Tomljanovic could not muster a similar performance against Świątek.
The Pole won 6-1, 6-2 in a largely routine affair on Centre Court.
The Australian qualifier showed a glimmer of life as the two traded breaks in the second set but the two-time French Open winner found her footing in the fifth game before wrapping up her 19th straight win on hard courts.
It was the second time the pair had met, with the only other clash also coming in Toronto, back in 2019.
That match also ended in a Świątek victory, but on that occasion it came when Tomljanovic withdrew from the match midway through the first set with an abdominal injury.
ABC/Reuters