The action is already heating up in both Doha and Dubai this week, as the world's top names made it past tricky competitors in their opening rounds.

These are the Top 5 Photos from Monday. (All photos Getty Images.)

1

Roberto Bautista Agut

After a tough first-round loss in Rotterdam, the Spaniard looked to be headed in a similar direction against American Reilly Opelka in his Doha opener. However, the 32-year-old flipped the switch in the second set to push the affair to a deciding set, and ultimately prevailed with a 4-6, 6-3, 6-4 victory.

Bautista Agut will next face Alexander Bublik for a spot in the 500-level event's quarterfinal.

Top 5 Photos 3/8: 
Bautista Agut fights
 past gritty Opelka

Top 5 Photos 3/8: Bautista Agut fights past gritty Opelka

Advertising

2

Garbine Muguruza

The two-time major champion continued to display the same excellent form that saw her to the Qatar Open's final round. Muguruza defeated Irina-Camelia Begu, 6-3, 7-5, to kick off her campaign in Dubai. The win sets up a first-time clash against American Amanda Anisimova.

Top 5 Photos 3/8: 
Bautista Agut fights
 past gritty Opelka

Top 5 Photos 3/8: Bautista Agut fights past gritty Opelka

3

Caroline Garcia

It was far from an easy day at the office, but then again, it always is when facing a major champion. Garcia managed to shake off a tough opening set to beat three-time Grand Slam champion Angelique Kerber, 3-6, 6-2, 6-4, in her Dubai opener.

Advertising

Top 5 Photos 3/8: 
Bautista Agut fights
 past gritty Opelka

Top 5 Photos 3/8: Bautista Agut fights past gritty Opelka

4

Aslan Karatsev

The Russian competitor began last season ranked No. 292 and now he sits at No. 45 in the rankings. Karatsev made some major noise at this year's Australian Open by roaring through qualifying and claiming five main-draw matches to reach the semifinals. On Monday, Karatsev ousted home hope Mubarak Shannan Zayid in the first round, 6-4, 6-0, to set up a second-round battle against Doha's No. 1 seed Dominic Thiem.

Top 5 Photos 3/8: 
Bautista Agut fights
 past gritty Opelka

Top 5 Photos 3/8: Bautista Agut fights past gritty Opelka

Advertising

5

Anett Kontaveit

The world No. 24 got off to a great start in Dubai by storming past Timea Babos, 6-2, 6-1, in their first career meeting. Kontaveit will take on Sorana Cirstea in a re-match of their Round of 32 Dubai encounter last season. The 25-year-old Estonian holds a 2-0 lead in their head-to-head record.

Top 5 Photos 3/8: 
Bautista Agut fights
 past gritty Opelka

Top 5 Photos 3/8: Bautista Agut fights past gritty Opelka