Coco Gauff outlasted Marta Kostyuk in a 3-hour, 8-minute marathon to reach the Australian Open semi-finals on Tuesday (23 January).

Gauff progressed 7-6 (6), 6-7 (3), 6-2 against the world No. 37 in a true test of tennis to reach her first semi-final here, remaining unbeaten in 2024 after 10 matches.

The two met for the second time in their careers. Gauff won in three sets in Adelaide two years ago.

The first set lasted longer than Gauff’s victory over Magdalena Frech in the previous round, running 1 hour, 16 minutes.

Gauff was down 5-1 to start the match but showed the heart of a Grand Slam champion by clawing her way back to wrest a 6-5 lead.

Kostyuk broke Gauff to force the tiebreak and had set point at 6-5 – yet was saved by Gauff, who went on to take the next three points and the set.

The grind continued in the second frame as they traded shot for shot, break point for break point and game for game as the set again clocked over an hour, this time Kostyuk capturing the tiebreak 7-3.

The third set proved to be all Gauff, who raced out to a 5-0 lead after breaking Kostyuk in the first, third and fifth games. She capitalised on her second match point.