Top 10 seeds Garbiñe Muguruza and Elise Mertens moved into the second round of the Dubai Duty Free Tennis Championships on Monday evening, although they took different paths to get there.

The No.9 seed Muguruza extended her recent run of stellar form with a 6-3, 7-5 victory over Irina-Camelia Begu.

But the No.10 seed Mertens had to survive a grueling two-and-half-hour marathon before prevailing over lucky loser Viktoriya Tomova 4-6, 6-2, 6-4.

2021 Dubai Highlights: Muguruza clinches first-round win over Begu

Former World No.1 Muguruza, coming off a runner-up showing at last week's Qatar Total Open, improved her 2021 win-loss record to 13-4 with her 96-minute win against Begu.

"It definitely was a challenge, because they’re definitely different tournaments and conditions," Muguruza said, with only two days off since her last match in Doha. "I’m just happy that I fought as much as I could, and closed the match in two sets."

Muguruza, making her seventh successive appearance at the Dubai Duty Free Tennis Championships, finished the match with 23 winners, compared to just 10 for Begu. Muguruza's best showings at the event are semifinal finishes in 2015 and 2018.

Stellar returning, including a clean winner on break point, helped Muguruza clinch a service break in the second game of the match, but Begu was able to pull back on serve despite an early 3-0 lead for the ninth seed.

A stirring backhand winner down the line gave Muguruza another break lead for 5-3, and she fired a collection of strong serves to consolidate the break with ease and grab the one-set lead.

Begu deployed an array of deft dropshots as the clash wore on, and she twice led by a break in the second set. Begu served for the set at 5-3, but a fortunate forehand winner off the netcord on break point allowed Muguruza to pull back on serve and extend the frame.

Muguruza would go on to use more powerful returns to break again for a 6-5 lead, and the Spaniard ultimately won the final four games of the match, ending the contest with a forehand winner.

"[Begu and I] have played before, we’ve also trained together, so we know each other’s games," said Muguruza, who improved to 4-1 against Begu. "I gave her a big battle and in important moments I tried to be very focused and be smart and efficient."

Next up for Muguruza will be American teenager Amanda Anisimova in the second round. In her first WTA event of the season, 19-year-old Anisimova dispatched qualifier Ana Konjuh, 6-2, 6-2. 

Elise Mertens plays her opening-round match at the 2021 Dubai Duty Free Tennis Championships.

Photo by WTA/Jimmie48

Mertens needed all of her grit to overcome lucky loser Tomova, who was a last-minute replacement for last week's Lyon semifinalist Fiona Ferro after Ferro withdrew from the event due to fatigue.

Presented with a second chance in the tournament, Bulgaria's Tomova pushed Mertens to the brink as she sought her first-ever victory over a Top 20 opponent. But Mertens finally claimed victory after a lengthy battle and improved her 2021 win-loss record to a superb 8-1.

Mertens, who won her sixth career WTA singles title at the Gippsland Trophy in Melbourne earlier this year, converted eight of her nine break points to counteract her 51 unforced errors and edge Tomova.

Tomova, in fact, had a whopping 17 break points during the clash, but had a much less robust conversion percentage, breaking Mertens six times.

After an array of breaks in the first set, Tomova came out on top in a six-deuce game to break Mertens for the fourth time in the opening frame and earn the one-set lead. However, Mertens regrouped in the second set, never dropping her serve in that timeframe as she leveled the match with a backhand winner down the line.

Still, the incredible defensive skills by Tomova kept the decider extremely competitive, as the lucky loser refused to yield in many long rallies, forcing errors from the Mertens racquet. Mertens had break leads of 1-0 and 4-2 but Tomova was able to reach parity both times.

A love break by Mertens for 5-4 was nearly squandered when she had to stare down two break points while serving for the match, but the seeded player finally held on for the win after a poorly-timed flurry of errors by Tomova to end the tilt.

Mertens will now face Shelby Rogers in the second round. In a hard-hitting clash, Rogers stopped qualifier Kaia Kanepi, 7-6(4), 6-2, to reach the second round.