PARIS -- Defending champion Serena Williams picked up a quick, clean victory to reach the third round of the French Open on Thursday.
Williams needed only 66 minutes to beat 81st-ranked Teliana Pereira of Brazil 6-2, 6-1, piling up a 31-6 edge in winners.
In the first set, Williams had 22 of those winners, compared to only three unforced errors.
Williams is trying to win her 22nd Grand Slam title, which would equal Steffi Graf's Open-era record.
Bertens, who upset Australian Open champion Angelique Kerber in the previous round, won the Nuremberg tournament last week as a qualifier.
"When I'm in a good position, I feel I strike it much better," said Ivanovic, who won in Paris in 2008. "Today that was the case. And I knew I had to be aggressive and move well against her, also take time away from her, because she's great player."
Bacsinszky, a French Open semifinalist last year, was broken in her first service game but rebounded to beat Eugenie Bouchard 6-4, 6-4.
Trailing 5-0 in the second set and with Bacsinszky serving for the win, Bouchard got back into the match, saving a match point and earning two break points that would have leveled the score at 5-5 but she failed to convert.
After making the semifinals at Roland Garros in 2014, Bouchard lost in the first round last year. From a career-high year-end ranking of seventh, the 22-year-old Canadian slipped out of the top 40 in 2015 and struggled with an eating disorder she says she has since conquered.
Bouchard attributed her early exit to her mind more than her tennis, saying "tennis is 90 percent mental" and that "the brain is like a muscle" that needs workouts. The 47th-ranked Canadian said her mentality used to be "my amazing strength" and that "I feel like I've not used that as much in the past year or so."
The Associated Press contributed to this report.