Roger Federer produced another sterling display to defeat Stefanos Tsitsipas and move one win away from his 10th Swiss Indoors Basel title at a raucous St Jakobshalle.

Twenty-time grand slam champion Federer has been in brilliant, bruising form all week in his hometown, even if he reached the last four thanks to compatriot Stan Wawrinka's withdrawal due to a back injury.

There was no let up against his toughest opponent yet as Tsitsipas failed to withstand the Swiss storm, going down 6-4 6-4 to the stylish top seed and nine-time winner.

Tsitsipas, taken to three sets by Filip Krajinovic in the quarters while Federer rested, was immediately under intense pressure as a partisan crowd backed their man to go on the offensive.

The Greek escaped from the first five break points he faced but there was no halting Federer, who forced his opponent into a corner from where he could only find the net on the sixth opportunity.

Tsitsipas did well to prevent further damage but could not get back on serve, before Federer blasted into the lead in the first game of the second.

The 21-year-old forged his first break point in the final game of the match as the veteran favourite recovered from the brief hiccup to serve his way to a straightforward but impressive triumph.

Alex De Minaur awaits Federer in the final after battling past Reilly Opelka in three tie-breaks, winning 7-6 (7-2) 6-7 (4-7) 7-6 (7-3).

"In the second set, I did everything right - he just came up with two very big points," the Australian said. "I knew I just had to say, 'Too good,' and get ready for the third set."

De Minaur added of the Sunday decider: "I can't wait. It's my first time here and it's been a hell of an experience. I'm really looking forward to coming out tomorrow and having some fun."

Having never won an ATP Tour title prior to this season, De Minaur has triumphed in his three final appearances in 2019.