Paul and Pegula are the first pair of Americans to take down the WTA and ATP World No.1 in the same week since Roddick and Serena in 2008.
A pre-match ritual has helped Alex de Minaur break through to his maiden Masters 1000 final.
The semis are set in Montreal after a long day of tennis.
Daniil Medvedev believes the tours need to find a way to standardize tennis balls at each event.
The Spaniard was blown away by the force of Ben Shelton's game in Canada
"Everything that I have done is thanks to him," Carlos Alcaraz said of Juan Carlos Ferrero.
The Scot sent Italy's Jannik Sinner into the quarterfinal with an abdominal injury.