The second seed won in three sets.
It certainly seemed to have done the trick for a set and a half for the 24-year-old, who looked on the verge of her biggest career win to date.
But Sabalenka came back to disappoint a raucous Centre Court crowd with a 4-6 6-3 6-3 second-round victory.
Not that the deciding set was a stroll for Sabalenka, although Boulter will rue a Hawkeye decision as she was about to walk back to her seat.
Sabalenka’s ball, called out, had in fact shaved the line by the width of a blade of grass.
Sabalenka duly broke – but in an epic seventh game Boulter forced six break points with some glorious shot-making, including an exquisite drop-shot and lob combination.
しかしながら, the 23-year-old from Minsk repelled the lot and brave Boulter’s chance had finally gone.
“It was a tough match, she’s an unbelievable player,” said Sabalenka. “It was a great atmosphere from the beginning to the end.
“Of course I was nervous today and didn’t feel the court from the beginning but I’m glad I got my rhythm in the second set.
“I have one question guys, will you support me like this in the next round?」