It was only a grass-court exhibition match at the prestigious Hurlingham Club, a 15-minute drive from Wimbledon, but world No.1 Sinner certainly looked in good nick as he defeated British No.1 Cam Norrie 6-3 6-3 on the sort of scorching day supposed to make life so uncomfortable for the pale Italian.
In the teeth of the hottest June day ever recorded in the UK -- temperatures were 33C (91.4F) on Wednesday and still rising in early afternoon - Sinner took to the court for his first match since his boilover second-round collapse from two sets and 5-1 up against Juan Manuel Cerundolo on May 28.
The temperature on Court Philippe-Chatrier in Paris had been 32C (90F) when Sinner, who'd been in complete control, began to struggle to cool himself down, having to reach for multiple ice bags as he felt dizziness, with his form subsequently falling off a cliff.
And although the Italian, who's had a history of problems with heat and cramps, didn't blame the heat entirely after the loss, suggesting it was a combination of factors, it's only prompted more searching question marks about his team's preparations for him to deal with the hottest conditions in grand slam five-setters.
But after beating Norrie, Sinner sounded relaxed about his SW19 prospects, even if the heatwave persisted, as he explained how his team, including Australian super coach Darren Cahill, had been working feverishly to make sure there'd be no repeat of the Cerundolo crash.
"Whether it will happen again, I don't know, I cannot predict the future," Sinner conceded. "But we are doing everything possible to make sure the chances are as low as possible.
"We've made some changes in practice and other things around it. Let's see how it works and how it goes.
"I had a week off with completely no tennis, no nothing. I didn't watch any matches and I didn't touch a racquet. I spent some great time with family and friends, which for me was the most important thing because I don't usually get much time to do that.
Earlier, Sinner had again been seen wearing a cooling vest at practice at Wimbledon but during the Norrie match, he wasn't using ice packs.
Sinner, who's lost just three of 40 matches this year, will again start overwhelming favourite at Wimbledon, where conditions are expected to be significantly cooler, around 24C, by the time the main draw action kicks off on Monday.
Having defeated then champion Carlos Alcaraz 4-6 6-4 6-4 6-4 in last year's final for his maiden Wimbledon crown, Sinner won't have to worry about his greatest rival this year as the Spaniard's out with a wrist injury that also prevented him defending his French Open title last month.
Meanwhile, another Wimbledon contender Taylor Fritz has decided to pull out of the Eastbourne Championship warm-up event, ending his chances of a hat-trick of titles at the seaside venue, following Brazilian star Joao Fonseca's earlier withdrawal. Both are expected to be fine for Wimbledon.
