Vondrousova came into the tournament on the back of an injury scare after a nasty fall forced her to retire early with a hip concern following her second-round match at the Berlin Open.

The sixth seed appeared to be feeling the after-effects of the problem, moving with difficulty.

Bouzas Maneiro capitalised on Vondrousova's physical struggles, breaking early in each of the first and second sets before firing a sublime backhand winner down the line on her first match point.

"I was just trying to enjoy the moment," said the Spaniard. "She is one of the best players in the world here, she won last year so I was like, I have no pressure, enjoy the moment, enjoy the tournament.

"I'm surprised with myself, honestly. I was at the beginning a little bit nervous, but since the first game, I don't know, the atmosphere was so nice, so elegant.

"I was comfortable playing here, it felt like I was playing at home."

Vondrousova also said she "felt the nervous from the start" and "was a bit scared" following her recent injury.

She added: "Credit to her. She was playing a good match, too. I didn't feel at my best. I think she didn't gave me many points for free."

Bouzas Maneiro will play compatriot Cristina Bucsa in the second round.