CHARLESTON, SC, USA - Kicking off her title defense just past 10 p.m., No.2 seed Kiki Bertens was at her efficient best on Tuesday night at the Volvo Car Open.

The World No.6 needed just 59 minutes to see off Italian qualifier Martina Trevisan to reach the second round, 6-2, 6-1. 

"It's always tough for the first match on clay," Bertens said after the match. "In the beginning, I was searching for the rhythm and not putting too much on the ball. 

"From there, I started playing a little bit more aggressive, and in the end, I was happy with my game."

The gulf in experience between the two players proved evident in the match overall, despite the fact that Bertens was contesting her first match on clay this season, and Trevisan was playing in her fourth of the week.

The Italian qualifier scored her first WTA main draw win in the opening round against Hungary's Fanny Stollar, who had upset Johanna Konta to reach the third round in Charleston a year ago, but won just one more game in the match from 2-2 in the opening set.

"It was really tough today, I guess everyone was struggling with the cold and also the ball was not bouncing so much. From 2-all, I think I played some good tennis," Bertens told after the match.

"When I started playing more aggressive, I saw she was struggling with the movement and I hit some more winners. Also, I think my serve was much better than hers."

Read more: Bertens returns to her happy place in Charleston: 'I feel more freedom on clay'

It was a tidy match for the Dutchwoman overall, as she hit 12 winners to 11 unforced while the Italian racked up 21 unforced errors to just eight winners.

After surrending serve for 2-2, Bertens lost just two points in two services games from then on in the opener, and dropped just three points behind her serve overall in the second set while not facing a break point. 

The No.2 seed is the beneficiary of a day off on Wednesday, and will next face either No.15 seed Maria Sakkari or former champion Andrea Petkovic.

"It's going to be tough for sure," Bertens said. "They're both great players. Petkovic is trying to come back still, and Maria is such a great fighter, so either way, it's going to be a tough match."