The Romanian was in ominous form as she clinched a dominant 6-0, 6-3 victory in just 71 minutes on the red clay of the Caja Mágica.

Kristýna Plíšková of the Czech Republic, who beat Spain's Sara Sorribes Tormo 7-5, 6-2, awaits for Halep in the last 16.

"I knew she was coming with a lot of confidence," Halep said. 

"I had to start very strong and aggressive, which I did. 

"After I played a few games I felt really good."

Elsewhere in the women's draw, Petra Kvitová of the Czech Republic continued her pursuit of a second straight title by overcoming Olympic champion Monica Puig.

Kvitová, who claimed the Prague Open crown on Saturday (May 5), had lost both of her previous encounters with the Puerto Rican but brought that record to an end with a 6-3, 7-6 victory.

Daria Kasatkina, the 14th seed from Russia, will take on the two-time Grand Slam winner in the next round after she defeated Halep's compatriot Sorana Cîrstea 6-3, 6-1.

In the men's draw, Dutchman Robin Haase sprung a first-round surprise as he knocked out Australian Open semi-finalist Hyeon Chung of South Korea.

Haase produced a superb performance on his way to thrashing his opponent 6-2, 6-0.

In the second round, Canadian Denis Shapovalov, fined for hitting an umpire with the ball during a Davis Cup tie last year, beat Frenchman Benoit Paire 7-6, 4-6, 6-4.