Turning over to the men's side, No 3 seed Grigor Dimitrov of Bulgaria triumphed over lucky loser Tennys Sandgren 7-5, 6-3.

Both players were strong on serve, with Sandgren notably serving eight aces during the course of the match. Dimitrov managed to break Sandgren in the decisive final game to take the first set.

The 2017 China Open semifinalist then raced into a 3-0 lead at the start of the second set and thereafter held the American at arm's length to see out the match in one hour 24 minutes.

Dimitrov's third round opponent this year will be Serbian qualifier Dusan Lajovic, who secured safe passage after beating Canada's Vacek Pospisil 2-6, 6-4, 6-4.

The next match saw No 1 seed Juan Martin del Potro defeat Spain's Albert Ramos 7-5, 6-2.

Del Potro trailed 2-1 in the first set, but rebounded to take the next three games to pull ahead 4-2 using that clearance to seal the first set.

From then on, momentum seemed to be with the Argentinian, who hit ten aces during the course of the match, ultimately wrapping proceedings up in one hour 30 minutes.

It was another nail-biter of a match between Spain's Fernando Verdasco and Gael Monfils of France. The Spaniard needed two tiebreaks to take the match 2-6, 7-6 (3), 7-6 (5) in two hours, 26 minutes.

Verdasco goes on to take on Georgian contender Nikoloz Basilashvili, who also needed three sets to take out No 6 American Jack Sock 7-6 (6), 5-7, 6-2.

Other action saw Italian qualifier Matteo Berrettini down Argentina's Leonardo Mayer in straight sets: 6-3, 6-2. Berrettini faces No 5 seed Kyle Edmund of Britain, who moved into the third round in yesterday's action.

Finally, the last match of the night saw No 2 seed Alexander Zverev defeat Roberto Bautista Agut in straight sets: 6-4, 6-4.

Some round-of-32 action continues tomorrow, with other matches in the third round also on tap.