Serena Williams, unseeded in her return to Grand Slam play after giving birth last year, defeated Kristyna Pliskova, 7-6 (7-4), 6-4. (Alessandra Tarantino/Associated Press)

Serena Williams attended the recent royal wedding of Prince Harry and Meghan Markle rather than play in the Italian Open, an important clay-court tuneup for the French Open. And though Williams isn’t technically a royal, posters advertising the French Open displayed a photo of her with the announcement, “The Queen is Back.’’

She is. And more accurately, “The Mother is Back.’’

Competing in her first Grand Slam since winning the 2017 Australian Open while pregnant, and in one of few tournaments since delivering her daughter last September, Williams defeated Kristyna Pliskova, 7-6 (7-4), 6-4, in her first-round match at Roland Garros on Tuesday.

“I feel like I’m on the right track,’’ Williams said. “I have been putting a lot of work in on the court, off the court, on the court, on the court, off the court — that’s kind of been my life. I have been really enjoying it. Hopefully the results continue to show.’’

Pliskova, ranked 70th in the world, said she expected Williams would not play as well as she did — the Czech player out-aced Williams — but the 23-time Grand Slam winner proved to be a tough opponent as usual. After the two were tied at 6 in the first set, Williams fell behind 3-0 in the tiebreaker but rallied to win 7-4 and hollered in triumph several times. She lost the first two games of the second set but came back to win six of the next eight to take the match.

“I knew that after Pliskova’s first game of serving, I said, ‘Okay, I have to serve really well today,’ ” Williams said. “ ‘I need to really be on my game serving-wise.’ ”

Williams had played just two previous WTA tournaments since giving birth to her daughter, Alexis Olympia. She lost in the third round at Indian Wells in March and in the first round at the Miami Open later that month. She backed out of the recent Madrid and Rome tournaments, saying she didn’t think she was ready to play.

In fact, because of postpartum medical issues, she said she occasionally wasn’t sure if she was going to make it back in the sport.

“A lot of people have really reached out, because they have so many similar stories, too,’’ she said. “I feel like a lot of people don’t talk about it. They talk about the baby and how happy they are. But it’s a lot that goes into it with the pregnancy and with giving birth and it’s called a miracle for a reason, because it’s a miracle and it’s very difficult sometimes to make it through.’’

Though she is back on the court, Williams said her emphasis is looking after her daughter: “No matter what, that’s my priority.’’

Because she missed so much time, Williams is ranked 451st after being No. 1 for much of the previous years, including when she took leave in February 2017. She was not seeded in this French Open, a fact that upset several players, including No. 1-ranked Simona Halep and rival Maria Sharapova.

Victoria Azarenka, who is working with the WTA as it looks into the issue, says that the news media is making a bigger deal out of it than it should, though.

“There are a lot of things that are going into this rule and into the thought process,’’ Azarenka said. “So I would like to just, for the record, say that please give us time and we will, as a woman association, make sure that we have the best for woman players, and for our sport there are a couple aspects to the seeding.’’

Azarenka also has a child and says that coming back from pregnancy is different from coming back from a tennis injury. It’s also harder on players who are mothers than players who are fathers, such as Roger Federer, who has two pairs of identical twins.

“It’s still unusual for women to have a family during their career, especially in tennis,’’ Azarenka said. “Physically, let’s start with that, is an experience that you go through, and men don’t go through the whole physical experience of becoming a parent.’’

Williams, 36, said that after delivering a child: “First and foremost, you have to get your core back, which is hard, because it literally spreads when you have a baby. That’s difficult. And just coming back from the physical part of having a baby, at my age, is never really easy.

“You know, emotionally I think it’s different, because I’m so emotionally attached to my daughter. Dads are, too, but I actually breast-fed for a really, really, really long time, and so I just had this real connection with my daughter. Yeah, so I think there are definitely some differences, but there is a lot of similarities, as well.’’

Williams will play her second-round match against 17th-ranked Ashleigh Barty, who is impressed by her opponent’s comeback: “What Serena’s done to be able to get back, along with Azarenka as well, and a lot of the other girls who are coming back after pregnancy, is a pretty amazing thing.’’

Williams made her return to the Roland Garros courts in a skintight black catsuit, and said she does so for a couple reasons. One is that the tightness of the pants helps her blood circulation. “I had a lot of problems with my blood clots, and, God, I don’t know how many I have had in the past 12 months,’’ she said. “So it is definitely a little functionality to it. I have been wearing pants in general a lot when I play so I can keep, you know, the blood circulation going.’’

Also, the suit makes her feel like a superhero. “I feel like a warrior in it, like a warrior princess, queen from Wakanda maybe.’’

So yes, the queen is back.