London-Sana
Greece's Stefanos Titipas advanced to the semi-finals of the London final with a 2-0 win over German Alexander Zverev.
The Greek broke his opponent in the eighth game after Zverev's performance slumped in the second half as Titipas clinched the match with a crushing 6-3 6-1 victory.
Titipas secured the first two places in the group, while world number one Zverev and Rafael Nadal will have to fight to join him in the semi-finals on Saturday.