Sinner, who won his last title on grass in Halle two months ago, will play a rare Monday final against the winner from Frances Tiafoe and Danish 15th seed Holger Rune.
Sabalenka will next face Italy’s Lucia Bronzetti, who advanced after New Zealand's Lulu Sun was forced to retire after losing the first set 6-3.
During the latest episode of WWE RAW, Adam Pearce announced a face-off between CM Punk and Drew McIntyre inside Hell in a Cell.
Shapovalov, 25, previously won in Stockholm in 2019 and made his last appearance in a final two years ago in Vienna.
Rohan Bopanna and Aldila Sutjiadi defeated John Pears and Katerina Siniakova 0-6 7-6(5) 10-7 to book their place in the mixed doubles quarterfinals at US Open.