Carlos Alcaraz stayed in the chase for a sixth trophy this season as the teenaged top seed booked his place in the semi-finals of the Swiss Indoors on Friday.

The world No. 1 Spaniard put personal feelings aside as he defeated his best friend on the ATP, Pablo Carreno Busta, 6-3, 6-4, to set up a Saturday semi with Felix Auger-Aliassime.

The on-form Canadian was equally solid as he put out Alexander Bublik 6-2, 6-3.

US Open champion Alcaraz is making his Basel debut, the event which Roger Federer won 10 times.

The Spaniard broke three times and dropped his own serve once as he beat his compatriot.

“It’s difficult to play against a friend like Pablo,” Alcaraz said.”Every day we go and have dinner, lunch together. 

“Every week we train together; I also support him and want him to win every match. 

“But on court, there are no friends. You have to be focused and go for the match and that is what I did.”

The winner has lost both of his previous matches to FAA – at the US Open last year due to an injury withdrawal and in Davis Cup last month in Valencia.

“It is going to be a really tough match,” Alcaraz said of the upcoming clash. “He is playing really well. He has had great victories this year. 

“I will have to be really focused. I will try to show my best tennis against him.”

Alcaraz stands 55-11 and will be playing his ninth Tour semi-final.