Paris - Angelique Kerber admitted the pressure of being world number one was beginning to eat away at her fragile confidence after becoming the first top seed in French Open history to lose in the opening round.
Kerber became the first top seed to lose in the first round at Roland Garros in the Open era, which began in 1968.
The German did not find herself as comfortable on the clay court as World No.40 Makarova, who broke her serve several times during the game.
The two-time Wimbledon champion's comeback ended in the second round of the French Open on Wednesday after a close match against qualifier Bethanie Mattek-Sands, who recorded her best result at a major in almost two years with a 7-6 (5), 7-6 (5) victory. "I'm very happy to be back on this court, which is probably the most important in my career".
But coming back at Roland Garros was probably a sensible decision, since the emotions at Wimbledon, where her expectations might be higher, could have been more hard to cope with. Now, in upcoming weeks, I think it will be business as usual.
She rallied from 3-1 down to take the second set to a tie-break but lost to the American on a double fault.More news: Samardzija knocked out early, Giants fall to Nats
"This year, I mean, the expectations are much bigger, especially in the big tournaments and the Grand Slams".
The 27-year-old, who dropped her racket and hid some tears behind her hands after match point, had spent five months out of the game since undergoing emergency surgery in December when she was stabbed during a home invasion.
Bacsinszky reached French Open round two after winning 6-1 and 6-2 over Sorribes in an hour and 22 minutes.
Kvitova, the 15th seed and a semi-finalist in Roland Garros in 2012, fired nine aces and 31 winners past Boserup, making her debut at the tournament at the age of 25.
Puerto Rican Monica Puig defeated Italian Roberta Vinci while Argentinian tennis player Horacio Zeballos stunned French Adrian Mannarino to advance to the second round.
The second set followed a similar pattern, with Kerber losing her serve twice to fall 0-3 behind. Petra Kvitova was originally expected to possibly return "sometime" during the grass season, with the hopes of playing the tournament where she's achieved her best results, at Wimbledon.More news: Irving's 42 carry Cavs to win, 3-1 lead over Celtics
Six months after being subjected to a terrifying knife attack in her own home, Kvitova returned to the court and won her first match at Roland Garros.
"I actually already won my biggest fight".
"I won for the second time, if I can say".
In Paris started the matches of the 116th version of the Open championship of France on tennis.
Others who moved on include eighth-seeded Russian Svetlana Kuznetsova and 10th-seeded American Venus Williams.
The fact that she's playing at all is a miracle, much less on the level she's playing.More news: PS Plus June 2017 Free Games: Here's what to expect next month