Stefanos Tsitsipas secures a fifth win in a row against Auger-Aliassime, battling past him 6-2 5-7 6-1 to reach back-to-back Cincinnati semi-finals.
The reigning Monte-Carlo champion secured a 6-2 5-7 6-1 victory over the 12th seed, fighting off a comeback after Auger-Aliassime took a close second set. The Canadian was undone by poor serving, as he committed seven double faults while winning only 38 of 55 points on his first serve.
Tsitsipas improves to a 5-2 record against the 21-year old, having won their last five consecutive meetings.
The Greek star will play Alexander Zverev as he beat off Ruud 6-1 6-3 only a moment ago.
This will set up a ninth career meeting with Tsitsipas in the Cincinnati semis