American Sloane Stephens has won the battle of former Grand Slam winners against twice Wimbledon champion Petra Kvitova, ousting the Czech 10th seed from the All England Club with a 6-3 6-4 victory.
The 2017 US Open champion came into the match on Centre Court with a 2-1 head-to-head lead against Kvitova, who lifted the Venus Rosewater Dish in 2011 and 2014, but all their previous meetings had been on hard courts.
"Obviously seeing the first round, I was like, 'Oh boy, this is going to be a difficult task'," Stephens said in her post-match interview on court.
"But knowing that I'll probably play on a big court and feeling good, I was excited to play against Petra."
A run to the quarter-finals in 2013 remains the best result at the grasscourt Grand Slam for 28-year-old Stephens.
Playing her first match on grass since the 2019 Wimbledon, the former world number three, who has slipped down the rankings to 73rd, showed no signs of rust against Kvitova as the sun finally came out after a soggy day.
"It's so special, obviously not playing on grass for two years and then being able to come back and my first match on grass is on Centre Court here with fans back is really just a dream," Stephens added.
"I love grass and it's just not really translated. It's been a couple of years since I've had a good result on grass but here is a good start, beating a really good grasscourt player, so I'm looking forward to more matches and hopefully I can get a good run here at Wimbledon."
After an early trade of service breaks, Stephens got a second which proved enough for the American to bag the opening set as Kvitova struggled to keep her first serve in.
The Czech, who injured her ankle in a freak fall while performing her media duties at the French Open earlier this month, appeared sluggish in her movements in the first set.
Kvitova had a big chance to nose ahead in the second when she had four break-point opportunities in the sixth game but Stephens held on and then picked up the crucial break in the next game to go up 4-3.
The American converted her first match point with a forehand winner which was found to have caught the line after a challenge from Kvitova.
She will next play either fellow American lucky loser Kristie Ahn or Britain's Heather Watson for a place in the third round.
Among the women, 2017 champion Garbine Muguruza sent out an early warning to her rivals with a blistering 6-0 6-1 win over Fiona Ferro, while American 23rd seed Madison Keys beat local hope Katie Swan 6-3 6-4.
Seventh seed Iga Swiatek of Poland overpowered Taiwan's Hsieh Su-wei 6-4 6-4 to secure her first main-draw win at Wimbledon. Joining her in the second round was Sofia Kenin, who made short work of Wang Xinyu 6-4 6-2.
Second seed Aryna Sabalenka of Belarus got her campaign off to a blistering start, beating Romania's Monica Niculescu 6-1 6-4 in 75 minutes under the retractable roof on Court One.
