Svetlana Kuznetsova upset the No.1 seed at the Dubai Duty Free Tennis Championships on Tuesday, as the two-time Grand Slam champion bounced two-time Dubai champion Elina Svitolina 2-6, 6-4, 6-1 to reach the round of 16.

Kuznetsova tore through the latter stages of the match to collect the comeback win in just under two hours. It was the top seeds Svitolina's opening match of the tournament (after a first-round bye).

Svitolina won back-to-back Dubai titles in 2017 and 2018, but Kuznetsova also has a strong history at the tournament. Kuznetsova has the most match-wins among active players at the event; the three-time Dubai runner-up earned her 21st with her upset win.

"I have no doubts I can compete against the best, so I just want to play and enjoy my game," Kuznetsova said in her post-match press conference.

Kuznetsova's win over World No.5 Svitolina is her first Top 5 victory since she beat then-World No.2 Ashleigh Barty and then-World No.3 Karolina Pliskova en route to the Cincinnati final in 2019.

Kuznetsova did not hold a break point during a fairly routine first set for Svitolina, but the former World No.2 turned the tables at the end of the second set, cracking a return winner to garner a set point at 5-4. Kuznetsova converted that chance after a wide forehand by Svitolina, and the match was all square.

"I was feeling so stressed out there in the first set, I couldn’t make any balls, the feeling was terrible," Kuznetsova said. "I was just focusing on trying to make two or three shots in, to see how I can go, how I can regroup, that’s it.”

With a bevy of heavy forehands, Kuznetsova went on a massive run, at one point winning eight games in a row as she stormed to a 5-0 lead in the decider. Svitolina saved two match points with bold aggression to get on the scoreboard at 5-1, but Kuznetsova held firm, fending off two break points in the next game to complete the upset.

2021 Dubai Highlights: Swiatek sizzles in Dubai debut over Doi

Swiatek, Muguruza set third-round clash: Reigning Roland Garros champion Iga Swiatek had a more straightforward path into the Dubai round of 16, as the No.8 seed eased past lucky loser Misaki Doi, 6-2, 6-4.

"Even though I was leading the whole match, I knew that I’d have to just work really hard, because first matches are always tricky," Swiatek said to the media after her win.

Swiatek needed an hour and a quarter to notch her sixth straight victory, having won the Adelaide title in her most recent event.

"I learned that I shouldn’t bring all the wins with me on court. I should just focus on a new match, like it’s a new journey.”

- Iga Swiatek

It was a dominant display by Swiatek with her first serve, as she won 21 of her 22 points when she got that shot into play. One of her six aces in the match closed out the first set over Doi.

In the second set, Doi used pinpoint accuracy and some divine passes to decrease her deficit from 5-1 to 5-4, but Swiatek was able to power her way to a love hold in the final game to secure victory.

Swiatek will now face No.9 seed Garbiñe Muguruza in an eye-opening third-round encounter, after Muguruza dispatched American teenager Amanda Anisimova, 6-4, 6-2.

In the first meeting between the two, it was Muguruza who held the upper hand throughout the hour-and-a-half encounter, converting four of her 12 break points while only dropping serve once.

"I feel like now I'm a little more open to adapt to new circumstances, more open mentally as well to face these challenges, so I feel like it’s a combination of things," Muguruza said. "Certainly experience, and now, I know how to deal with myself more as well. I’m very happy with the consistency so far."

Muguruza - 2021 Dubai 2R - Jimmie

Garbiñe Muguruza plays her second-round match at the 2021 Dubai Duty Free Tennis Championships.

WTA/Jimmie48

Former World No.1 Muguruza needed just the single break of serve to claim the one-set lead, though things got tricky in the early stages of the second set as she and Anisimova traded breaks in the first two games.

However, Muguruza turned the tide heavily in her favor from there, using powerful play to wrap up five of the next six games and set up her first meeting against a 19-year-old for the second round in a row.

"Of course, last year [Swiatek] won the French Open, so she had a big breakthrough," Muguruza said while looking ahead to the round of 16. "It’s never easy to go out there and win a Grand Slam, so tomorrow I’m going out there and playing a very good player, and looking forward to that."

"I’m happy that I get to play a player that I didn’t play for whatever reason, the draw or something, and top players especially," Muguruza added.

Teichmann moves on as Kvitova retires: Muguruza's conqueror in last week's Qatar Total Open final, Petra Kvitova, was unable to claim a win this week, as the Czech retired to Jil Teichmann while the Swiss led 6-2, 3-4.

"Since my semifinal in Doha, I felt my adductor," said Kvitova, after the retirement. "It didn't get any better in the second set, it just got a little bit worse and I felt pain almost everywhere on the right leg. So, unfortunately, I couldn't really move how I wanted, and I didn't want to get it even worse. So that's unfortunately why I retired."

2013 Dubai champion Kvitova saw her four-match winning streak halted by her retirement, as Teichmann's solid returning pulled her ahead and eventually garnered her a second career victory over a Top 10 opponent.

Teichmann clocked return winners on break points twice in the first set as the World No.54 powered her way to a commanding 4-1 lead in the all-left-handed affair.

At that point, Kvitova received treatment on her leg while she stared down the deficit, but Teichmann remained focused and fired an ace on her third set point to close out the opening frame.

A Teichmann double fault on break point gave Kvitova the early advantage as the two-time Wimbledon champion moved ahead 4-1 in the second set. However, one more cracking return winner on break point sealed yet another break for Teichmann as she pulled back on serve at 4-3. At that juncture, Kvitova deemed herself unable to continue.