Sophia Popov winning the Women's British Open was a surprise in many ways.

Except for one.

First-time major champions — even those not among the top 50 in the world — are nothing new on the LPGA Tour. A month after Popov won at Royal Troon as the No. 304 player in women's golf, Mirim Lee was No. 94 when she won her first major at the ANA Inspiration by beating Brooke Henderson and Nelly Korda (both in the top 10) in a playoff.

Going into the Women's PGA Championship, which starts Thursday at Aronimink outside Philadelphia, eight of the last nine major champions had never won one before.

The exception was Jin Young Ko, who won two majors last year. Ko is the No. 1 player in the women's world ranking, and the No. 1 absentee in the majors this year as she rides out the COVID-19 pandemic at home in South Korea.

Would it have mattered if Ko had kept playing after sweeping all the big awards last season? Maybe. But recent history is not on her side even in healthy times. Since the retirement of Annika Sorenstam in 2008 and Lorena Ochoa two years later, players who reach the top — Yani Tseng, Inbee Park and Lydia Ko come to mind — don't stay there long.

That also speaks to the depth of women's golf.

“I think on any given week, a girl that's ranked 200 or 300 can play her best golf and win,” Popov said Tuesday. "I wouldn't say it's not like that on the men's tour. Every now and then, you have a breakout winner, you have a surprise winner that no one was talking about previously.

“The surprise factor is always going to be there,” she said, “but I'm not surprised about any of the girls winning this week.”

Popov stands out for other reasons.

Part of the national championship team at USC in 2013, she was an LPGA rookie in 2015 when she began suffering from fatigue and lost some 25 pounds. It took three years and 20 trips to the doctor to be diagnosed with Lyme disease.

She was on the Symetra Tour at the start of the year when the pandemic shut down golf. One of the few options to play was the satellite Cactus Tour, where Popov won three times. When the LPGA Tour resumed, she went to the first event as a caddie for good friend Anne van Dam. And because so few international players were traveling in August, Popov got into the field at the Marathon Classic. She tied for ninth, earning a spot in the Women's British Open.

So yes, that was a surprise victory on many levels. And Popov, who was born in Germany, has been celebrating ever since.

A year ago, the Women's British Open delivered another surprise — Hinako Shibuno, in her first competition outside Japan. And then there's Hannah Green, who came to the Women's PGA at Hazeltine last year at No. 114 in the world, coming off a bad week and hopeful of making the cut. She went wire-to-wire, holding her nerve all the way to the end.

“Once I put myself in contention and put myself with the lead, that’s when I kind of said to myself: ‘I can win this. There’s no reason why I can’t,’” Green said. “Yes, I hadn’t been in that position many a time before, but because it’s a major championship, everyone is feeling the pressure just as much as I was.”

Pernilla Lindberg was at No. 95 in the world when she outlasted Inbee Park on the eighth hole of a playoff at the 2018 ANA Inspiration. Angela Stanford was 40 and six years removed from her last LPGA win when she captured the 2018 Evian Championship while ranked No. 76.

Majors always deliver an out-of-the-blue winner, men and women. Mo Martin won the Women's British Open in 2014 when her 3-wood hit the pin on the closing hole at Royal Birkdale. Birdie Kim won the U.S. Women's Open at Cherry Hills in 2005 by holing a bunker shot on the 18th hole.

Now, it seems to be happening more often.

It wasn't like that two decades ago. There was a stretch from the summer of 1998 through the end of 2002 when the only first-time major winner was 24-year-old Karrie Webb in 1999. Two years later, Webb had the career Grand Slam, and six years later she was in the Hall of Fame. That didn't rate as a big surprise.

No one dominated women's golf back then, either. It was simply a small collection of future Hall of Famers — Webb, Sorenstam, Juli Inkster, Se Ri Pak — taking turns winning majors.

Lydia Ko is the last woman to win consecutive majors, at the Evian Championship in 2015 and at the ANA Inspiration the following April. She was only 18 at the time. She was No. 1 in the world. She has only three wins, no majors, since then.

“I think every year people are getting better and better and better,” Ko said. “And you think, ‘How can they get better from there?’ And they players do. That's why even the No. 1 player in the world or No. 100, everyone is putting in time grinding it out to just make them a little bit better. And I think that's the direction where everyone is heading.”