Roger Federer looks to maintain remarkable record in Swiss Indoors as he takes on unseeded Alex de Minaur in final

The 20-time grand slam winner, who defeated Tsitsipas in the semi-final, has not lost in Basel tournament since 2013

Roger Federer celebrates after beating Stefanos Tsitsipas in the Swiss Indoors semi-final on Saturday. Reuters

Roger Federer will look to continue his remarkable record in the Swiss Indoors on Sunday when he takes on unseeded Australian Alex de Minaur in the final.

Federer beat Greek third seed Stefanos Tsitsipas 6-4 6-4 in the last four in Basel on Saturday, where he has now won 23 matches in a row and made the final in his last 13 appearances – the 15th overall. His last defeat came in the 2013 final at the hands of Juan Martin del Potro.

The 38-year-old top seed, who has yet to drop a set in this year's tournament, will be looking to seal a 10th title in his hometown – the 157th tour-level final of his career. Beating Tsitsipas was also a record 16th time that Federer has won 50 ATP tour games in a season.

The Swiss former world No 1 did not drop serve – with high win percentages on his first (80 per cent) and second serve (85 per cent) – and he broke the 21-year-old twice in the 78-minute contest.

"Having the crowd behind you really helps you believe in your game," said Federer, who had also defeated Tsitsipas in Dubai earlier this year.

"I had to play aggressive and take risks against Stefanos. There was a lot of running. But it's always easier to play at home, I was energised."

Earlier, De Minaur beat big-serving American Reilly Opelka 7-6, 6-7, 7-6 in the first semi-final

The 20-year-old Australian who prevailed in the tiebreaks to advance to his sixth ATP tour final and his fourth of the year, having already won titles in Sydney, Atlanta and Zhuhai.

De Minaur, who trains and lives in Spain, is the first Australian to reach the Basel final since Mark Philippoussis finished runner-up in 1997.

De Minaur, who measures up at 1.80m compared to Opelka's towering 2.11m, set up his semi-final victory with a passing winner for four match points.

Opelka saved the first with an ace but was caught out on the second as his opponent sealed the win.

"Nothing can prepare you for that serve," De Minaur said. "Reilly's an incredibly tough competitor who never gives up. I'm just happy to be in the final. I guessed right a few times and got lucky. I was just lucky to have gone the right direction, I was just hoping not be hit by any of those serves."