Two-time Swiss Indoors champion Juan Martin del Potro survived a battle with Spain’s Roberto Bautista Agut, winning 6-2 2-6 6-4 to move to his third straight semi-final of the season.

Fourth-seeded Argentine del Potro will wait for a Saturday opponent as second seed and defending champion Marin Cilic takes on Hungarian Marton Fucsovics.

Top-seeded seven-time champion Roger Federer was playing Frenchman Adrian Mannarino, with the Swiss holding a 4-0 lead in that series.

Del Potro reached the semi-finals this month in Shanghai and won a second Stockholm title last weekend in a late-season hot streak.

The Argentine has a chance to qualify for next month’s eight-man ATP Finals in London should he lift a third Basel title to go with the pair he won over Federer in 2012 and 2013.

Del Potro found himself struggling in the third set after sixth seed Bautista Agut had levelled the match at a set each through two breaks in the second set.

Del Potro put his nose ahead for good as he broke for 5-4 to end a game lasting for more than seven minutes and served out the victory a game later on his first match point.