No.5 seed Anett Kontaveit fought back from a one-set deficit before advancing to the second round of the Porsche Tennis Grand Prix, defeating two-time champion Angelique Kerber 3-6, 6-4, 6-4 in Stuttgart on Wednesday.

It took just over two hours for 2019 Stuttgart runner-up Kontaveit to overcome former World No.1 Kerber, the top German player on tour. Kontaveit is now 5-1 overall against three-time Grand Slam champion Kerber.

By the numbers: With the victory at the indoor clay event, Kontaveit has now won 21 consecutive matches indoors. The streak includes titles at Ostrava, Moscow, and Cluj-Napoca last year, and another title in St. Petersburg this year.

The comeback triumph starts Kontaveit's clay-court season off splendidly, and ends a two-match losing streak for the Estonian. After beginning the season 13-3, Kontaveit lost two of her three matches in the Sunshine Double of Indian Wells and Miami.

Each player broke serve four times in the closely-contested affair, but Kontaveit held on down the stretch, fending off a third-set surge by Kerber. Kontaveit had 37 winners to just 24 unforced errors in the clash between the Top 20 players.

Kerber, who won back-to-back titles on home soil in Stuttgart in 2015 and 2016, only won one fewer point than Kontaveit in the match as a whole. But Kerber was ultimately undone by 30 unforced errors, outpacing her 26 winners.

More from Wednesday in Stuttgart:

Stuttgart: Kontaveit outlasts 2-time champion Kerber

2022 Stuttgart

Match breakdown: Kerber got off to a flying start in the opening frame, leaping ahead by a double-break to 4-1 before holding on for a one-set led. Kontaveit, though, rebounded in the second set, earning the lone service break in the opening game.

In the decisive third set, Kerber came back from 0-40 down to hold in the first game, but Kontaveit used her powerful play to break Kerber in the German’s next two service games and lead 4-1.

Kerber found some of her signature winners down the line to prolong affairs in the third set, even grabbing one of the breaks back. However, Kontaveit stayed solid and found divine forehands during the 5-4 game to help her serve out the match and attain victory.

Next up: Kontaveit will face another big hitter in the second round when she takes on Ekaterina Alexandrova. Kontaveit has won both of their previous meetings, both also coming indoors. However, Kontaveit needed to go down to the wire before eking out each of those wins.

Former champion Siegemund stops Zidansek

Laura Siegemund, another former Porsche Tennis Grand Prix champion from Germany, was also in action on Wednesday night. Siegemund won her opener 6-3, 6-3 over 2021 Roland Garros semifinalist Tamara Zidansek of Slovenia.

Siegemund, who was Stuttgart runner-up to Kerber in 2016 before claiming the title the very next year, took an hour and 27 minutes to oust World No.27 Zidansek.

The win is Siegemund's first tour-level main-draw match-win of the 2022 season, after returning from a right leg injury. It is also wildcard Siegemund's first win against a Top 50 player in over a year.

Next up for Siegemund is a second-round tussle with No.4 seed Maria Sakkari, which will be their first meeting. Former World No.27 Siegemund will be aiming for the tenth Top 10 win of her career, and her first in nearly five years.