Quarterfinal action starts on Day 8 of the BNP Paribas Open as Australian Open champion Aryna Sabalenka takes on Roland Garros finalist Coco Gauff, and last year's runner-up Maria Sakkari faces two-time Wimbledon winner Petra Kvitova. Here's how the matchups break down.

More from Indian Wells: Scores | Order of play | The best of Week 1 | Gauff, Sabalenka survive | Kvitova saves match points | Swiatek stops Raducanu 

[7] Maria Sakkari (GRE) vs. [15] Petra Kvitova (CZE)

Head-to-head: Sakkari leads 4-3 (including 3-2 on outdoor hard courts)

The presence of Maria Sakkari and Petra Kvitova in the quarterfinals is testament to both players' grit. Who's battled harder to get here? Call it a tie.

Sakkari has been taken to three sets in all of her matches so far. In her first two, she needed to come from behind to defeat Shelby Rogers and Anhelina Kalinina -- against whom she had been a combined 0-4. In the fourth round, she quelled Karolina Pliskova, who had routed her 6-1, 6-2 in Dubai three weeks ago in a match that lasted 2 hours and 43 minutes.

Great Escapes 2023: Winning from match point down

Kvitova has arguably had a wilder ride. She came from 5-3 down in the second set to defeat Elizabeth Mandlik in her opener, then came out on top of two remarkable score lines, 0-6, 6-0, 6-4 against Jelena Ostapenko and 6-2, 3-6, 7-6(11) against Jessica Pegula, saving four match points in the latter.

"I just tried still be aggressive but not always was there for me," Kvitova said afterward. She's now in the Indian Wells quarterfinals for a third time, having lost at that stage in 2013 to Maria Kirilenko and in 2016 to Agnieszka Radwanska.

The pair's head-to-head has swung back and forth, with four of the pair's first five meetings went to a third set. Sakkari has the momentum in the rivalry, though. She has won their past two encounters in straight sets, including a 6-3, 6-0 win in the third round here last year. The 2022 finalist is still on course to repeat that performance.

[6] Coco Gauff (USA) vs. [2] Aryna Sabalenka

Head-to-head: Gauff leads 3-1 (including 2-0 on outdoor hard courts)

Both Coco Gauff and Aryna Sabalenka have ticked off another milestone this fortnight after reaching the quarterfinals here for the first time. Sabalenka has now reached at least the last eight of every WTA 1000 event except Guadalajara, which was only inaugurated last year.

How a first-time major winner responds to their new status is always an intriguing narrative. The answer has varied over the years. The freshly crowned Australian Open champion Sabalenka has settled quickly into her new role, though, bolstered by her stay in the Top 10 for over four years previously.

"I'm really glad that I won my first Grand Slam in this age," she said after beating Barbora Krejcikova in the fourth round.

"I felt like if I would be 18 years old to win the Grand Slam, then I would be struggling for years. I understand that, yeah, that's happened and that was my dream. It was amazing moment, but time to move on. It's another tournament, it wasn't the only one goal. 

"I have this understanding that no matter what, I have to keep going, keep fighting, and keep showing my best tennis if I want to keep winning. So for me it wasn't that tough."

coco gauff
More Head to Head
60% Win 3
- Matches Played
40% Win 2
aryna sabalenka

Sabalenka's ability to move on was evident in her defeat of Krejcikova. Having lost from 6-0, 3-1 up to the Czech in Dubai, she was at risk of a similar loss here after Krejcikova came back to level at a set all. But it was Sabalenka who regained the momentum to edge the decider.

She'll also need to move on from her previous results against Gauff. Their matches have tended to be close -- three have gone to a third set, and two of those to a deciding tiebreak. But it's tended to be the American teenager, who will be playing her first match as a 19-year-old, who's been more composed on the biggest points.

Gauff, whose rise in 2019 was characterized by a never-say-die attitude as she battled through a series of three-setters, showed the same spirit in the fourth round here, denying qualifier Rebecca Peterson from 4-2 down in the decider. Sabalenka will be able to overpower Gauff for stretches of their quarterfinal, particularly in forehand exchanges -- but can she out-clutch the teenager if it comes down to the wire?

Toronto: Gauff defeats Sabalenka in 3:11, longest match of career

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