Coco Gauff channels coach Brad Gilbert, wins ugly over Marta Kostyuk at Australian Open

Coco Gauff’s coach Brad Gilbert literally wrote the book on Winning Ugly, and the No. 4 seed took a page from that playbook on Tuesday when she navigated a messy Australian Open quarterfinal against Marta Kostyuk, surviving, 7-6 (6), 6-7 (3), 6-2 to reach her first semifinal Down Under.

"I'm really happy and proud of the fight I showed today," Gauff said on court after the match. "Marta's a really tough opponent; every time we play it's tough match. I really fought and left it out on the court today."

The reigning US Open champion has now won 12 straight Grand Slam matches and improves to 10-0 in 2024, saving two set points in the opening set and shaking off a second-set hiccup to ultimately clinch the error-strewn affair in three hours and eight minutes on Rod Laver Arena.

Gauff, still just 19, has been one of the most in-form players of the tournament heading into the quarterfinal stage, looking stronger and more confidence since capturing her maiden major victory last summer in Flushing Meadows. Easing into the second week without dropping a set, she lost two games or less in her last five sets to book an intriguing last-eight clash with Kostyuk, a former junior champion in Melbourne.

Kostyuk is also in the midst of a career-best stretch, saving match points against No. 25 seed Elise Mertens in the second round before rounding into form by the second week, dropping a 6-1, 6-2 scoreline on Maria Timofeeva to make her first Grand Slam quarterfinal.

Looking to take full advantage of the new plateau, Kostyuk set to work on the Gauff serve, breaking the American for the first time in three matches and capitalizing on her vaunted opponent’s clear discomfort to nab a commanding 5-1 lead.

But nerves soon set in for the 21-year-old from Kyiv, who has been at the forefront of advocating for the Ukrainian cause since the beginning of Russia and Belarus’ unprovoked invasion into her homeland. Those nerves manifested in some wild errors, and Gauff steadied just enough to save a set point and reel off five straight games to find herself serving from the opening set.

Kostyuk recovered to break straight back, and after a medical time out to address a foot injury, earned another set point in the ensuing tiebreak. But a missed forehand handed the initiative back to Gauff, who thrilled the crowd with one last comeback to clinch the first set in just over an hour.

The erratic duo exchanged breaks early in the second set, but Kostyuk struggled to contain her frustration as opportunities to advance continued to evade her. Failing to convert break point chances in the fifth game, the Ukrainian screamed to the heavens, and was only more dismayed when Gauff managed to break in the very next game.

To her credit, Gauff played a very mature match despire her own dips in play and losing the longest and highest-quality point of the afternoon, breaking Kostyuk a third time in the second set to put herself four points from the final four.

On the brink of defeat, Kostyuk rallied with aplomb, nailing a backhand pass to put the set back on serve and dominated the subsequent Sudden Death to force a final set.

Gauff reclaimed the momentum to kick off the third, emerging from a pair of long games to earn a double-break advantage over an increasingly frustrated Kostyuk, who threw her racquet as she fell behind 0-40 on serve in the third game.

The demolition continued as Gauff moved ahead 5-0, only for Kostyuk to again come alive at the 11th hour and claw one of the three breaks back, but the comeback proved too little, too late and Gauff served out the riveting and often ugly contest on her third attempt.

Up next for Gauff is a potential rematch of her US Open final against Aryna Sabalenka; the No. 2 seed must first defeat 2021 Roland Garros champion Barbora Krejcikova during Tuesday's evening session.