Former Top 10 player Flavia Pennetta had her game face on for the semifinals on Saturday afternoon.
Despite going down a set and a break, Johanna Larsson managed to beat the former No.10, 26 63 64.
Larsson is Sweden's No.1 player and was the No.8 seed at her home event, the Collector Swedish Open.
Larsson was through to her third WTA final, but had been a runner-up in her first two finals...
Meanwhile, Serena Williams had her game face on as she prepared for her semifinal match on Saturday.
Her opponent, Klara Zakopalova, had not only beaten her before, but it was on red clay, as well.
But while the first semifinal between Larsson and Pennetta was a long, grueling three-setter...
The No.1-seeded Williams rolled past the No.3-seeded Zakopalova in a high quality two-setter, 60 64.
Zakopalova came back on Sunday and won the doubles, though, alongside Anabel Medina Garrigues.
Medina Garrigues now has a whopping 21 WTA doubles titles to her name - Zakopalova has two.
Then, the singles final...
Larsson was twice up a break in the first set, but from 4-3 up, Williams' floodgates opened...
Williams won nine of the next 10 games from 3-4 in the first set to put Larsson away in two, 64 61.
Some lucky fans got a piece of Williams after the World No.1 claimed her 53rd career WTA title.
Williams now has 51 match wins on the year - she had never had more than 38 at this point of a year.