Karolina Pliskova passed a stern test from lucky loser Tamara Korpatsch before winning 7-5, 3-6, 6-3 in the first round of the Porsche Tennis Grand Prix.

No.6 seed Pliskova, the 2018 champion in Stuttgart, won the first set from a break down, lost the second from a break up and needed two attempts to successfully serve out victory in the decider. Balancing seven aces with eight double faults, the Czech eventually moved through in two hours and 18 minutes to set up a second-round clash with either Jelena Ostapenko or Stefanie Voegele.

World No.137 Korpatsch was playing her second Stuttgart main draw, having qualified in 2017, and seeking her first victory above WTA 250 level. The German had peaked at No.107 in August 2019 after reaching her first WTA semifinal in Lausanne that year, but has struggled since the Tour resumption. Coming into the tournament, Korpatsch was on a seven-match losing streak dating back to Prague last August.

Korpatsch had snapped that against World No.946 Alexandra Vecic in the first round of qualifying, but followed that with a 2-6, 6-3, 6-0 loss to unranked 18-year-old Julia Middendorf. This wasn't the most promising backdrop to a first career meeting with a Top 10 player, but the 25-year-old got off to a confident start on her home turf.

Finding sweetly angled winners and several well-disguised dropshots, Korpatsch exploited a sluggish Pliskova's movement to leap out to a 5-2 lead. But the former World No.1 began to find her range just in time. Pliskova rained down her first four aces of the match en route to reeling off five consecutive games to snatch the set.

Errors had begun to creep into Korpatsch's game as she had attempted to close the opener out, and she continued to look shaky in the second set as Pliskova raised her game. But having got the break for 3-2, Pliskova threw in a pair of careless service games to squander her advantage. This time, Korpatsch made no mistake in serving out the set.

But a flurry of unforced errors got Korpatsch off on the wrong foot in the decider, while Pliskova tightened up her own game to race into a 5-1 lead. Another bunch of cheap mistakes prevented Pliskova from closing out the win at the first go, but she regained her focus to seal the win the second time around.

Afterwards, Pliskova was dissatisfied with her tennis.

"First of all, super happy that I'm through," she said. "But other than that, I didn't see many really good things. Maybe there were a couple of good points, but it was not the best performance. I think she was also playing a bit tricky, all of these high balls, and [also] still getting used to the clay.

"I was struggling a bit in the rallies. I thought there were too many errors from easy balls, but I thought my serve was quite OK. Maybe two games were not so good. But a lot of things have to improve until tomorrow."

Pliskova said that Korpatsch, having had two matches under her belt this week already, had been able to play without pressure.

"She had completely nothing to lose, so I think she actually played a good match. She didn't give me much super-easy mistakes, but also she didn't really put any huge pressure on me. She was not serving big, she was not killing my second serves. So, it was mostly about me - what I'm going to do if I take the step in to dictate, or if I miss a bit. So, I felt like it's more in my hands but... she was moving well, she was fighting. So, of course, you have to give her credit."

In another match pitting a former champion against a lucky loser, 2015-16 titlist Angelique Kerber had a smoother passage against Ekaterine Gorgodze. Kerber delivered a clean performance, landing 78% of her first serves and tallying 23 winners to nine unforced errors, to progress 6-2, 6-2 in one hour and 12 minutes.

The Georgian World No.215 was playing her third career WTA main draw and looking for her first win, and impressed with her aggressive intent. But despite matching Kerber with 23 winners, Gorgodze also committed 24 unforced errors, and was able to convert only two of her 10 break points. Former World No.1 Kerber sealed her second match point to set up a second-round showdown against No.4 seed Elina Svitolina in what will be the 14th edition of the pair's rivalry.

Elsewhere, 2017 Roland Garros champion Jelena Ostapenko overcame a 0-2 head-to-head to notch her first win against qualifier Stefanie Voegele 6-4, 7-5. Ostapenko had lost to the Swiss player twice back in 2015, but edged their first meeting at WTA main draw level in one hour and 35 minutes to set up a meeting with Pliskova.

Kerber holds off surging Gorgodze in Stuttgart: Highlights