Coco Gauff is through to the semifinals of the Australian Open for the first time in her career after a hard-fought 7-6(6), 6-7(3), 6-2 win over Ukraine's Marta Kostyuk on Tuesday inside Rod Laver Arena. 

Both players were contesting their first Australian Open quarterfinal -- with Kostyuk in the midst of her deepest run at any major.

Gauff, the reigning US Open champion, won her 12th straight match at a Grand Slam, but it didn't come easily. The No.4 seed was 5-1 down in the first set and saved two set points -- one in her service game when she was trailing 5-2, and more than a half-hour later, at 6-5 down in the tiebreak -- before stealing the opener. 

"Obviously sometimes when you're down 5-1 you're not expecting to win the set," Gauff told reporters. "I believe every point, every game matters, and eventually the score started to get closer."

In the second set, she was an early break behind and failed to serve out the match in the ninth game. She regrouped with a strong start in the third and hardly looked back to eventually take victory in 3 hours and 8 minutes.

Gauff will now take on Aryna Sabalenka in the semifinals. 

Here are some notable stats from Gauff's win:

10: In addition to 12 straight match-victories at Grand Slams, Gauff has now improved her 2024 record to 10-0. She won five matches to take the title in Auckland in the season's first week and has added five straight-set wins in Melbourne.

3: Gauff is through to the third Grand Slam semifinal of her career, and they've come at three different majors. She's 2-0 in her previous two, having reached the final at Roland Garros in 2022 before winning the US Open last year. The one missing from her set is Wimbledon, where she famously reached the fourth round on her debut as a 15-year-old in 2019. 

3:08: The first of the quarterfinals is the fourth Australian Open women's singles match this year to last more than three hours (Swiatek def. Collins, R2; Frech def. Saville, R1; Siegemund def. Alexandrova, R1). 

Entering the match, Gauff had spent 4 hours and 48 minutes on court. Kostyuk had logged nearly twice that time (8 hours, 44 minutes) and played three three-setters in four rounds.

49: Playing her 18th career Grand Slam main draw this fortnight in Melbourne, Gauff now boasts 49 wins at majors. Since 1990, only Jennifer Capriati (50) has won more Grand Slam singles matches among American teenagers than Gauff and Serena Williams.

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2: Gauff is now 2-0 against Kostyuk in her career and both of those wins have come on Australian soil. She also beat her in a tight three-setter in Adelaide in 2022. 

5: Kostyuk is one of five Ukrainian women to reach a Grand Slam quarterfinal. The others are Elina Svitolina, Lesia Tsurenko, Kateryna Bondarenko and Dayana Yastremska -- the last of whom will face Linda Noskova in the last eight on Wednesday.

7: Kostyuk drops to 0-7 in her career against Top 5 players at majors.

6: Kostyuk saved the first five break points she faced -- two in the opening game, and 0-40 at 3-1 -- en route to building a 5-1 first-set lead, but by the end, the set saw six breaks of serve. Serving for the opener the first time, the Ukrainian hit back-to-back double faults to hand Gauff her first break. 

9: Nine points went against the server in the first-set tiebreak. Gauff had leads of 4-2 and 5-4 before rallying to win the last three points.

4: In the second-set tiebreak, Kostyuk won the first four points after successfully serving to stay in the match twice. She sent the match to a final set after converting her second set point.

12: Though Gauff landed only 43% of her first serves in the decider, she was a perfect 12-for-12 behind it in the set. 

39: Overall, Gauff stood tall on defense in the face of 39 winners from Kostyuk's racquet.