'S-HERTOGENBOSCH, Netherlands - The advent of the 2019 grass season has been a distinctly soggy one, with hours of rain delays afflicting tournaments across Europe - but the flipside for Kirsten Flipkens was that, with her beloved lawns underfoot at last, she could show off all her finesse in a 7-6(8), 7-5 upset of No.4 seed Lesia Tsurenko in the second round of the Libéma Open.

The Belgian, who was runner-up here to Simona Halep in 2013 and to Aleksandra Krunic last year, came from a break down in both sets to extend her head-to-head lead to 4-1 against Tsurenko and reach her fifth 's-Hertogenbosch quarterfinal in one hour and 58 minutes.

"It was a little bit of a rollercoaster," said Flipkens afterwards. "I did what I had to do tactically, I was able to play my game and come the net. I was trying to play point by point and that helped me in the first set and again in the second - I knew everything was close, even though the serve on grass is important. Every game in the second set was close, and I had the feeling I could break her - so I was not really down, I knew I would get my chance."

Torrential rain in the morning meant that the players only took the court over two hours after their intended start time - and even then had to endure another 15-minute delay midway through their warm-up for another last shower to pass. Unsurprisingly, the opening stages of the match were somewhat patchy. After an error-strewn exchange of breaks, it was the Ukrainian who settled first, nullifying Flipkens' serve-and-volley tactic with pacy returning and capturing the first break as the Belgian struggled to find her usual touch on the dropshot.

Once Flipkens began to construct points with some more care, though, the World No.69 was able to showcase a classic grass-court repertoire en route to turning the set around. Swarming the forecourt at every opportunity, Flipkens' skill and creativity at net was a delight.

Meanwhile, the Tsurenko serve was oscillating between weapon and weakness. The Brisbane finalist would be broken back on a double fault, but would save two set points - one at 4-5 and a second at 6-7 in a marathon tiebreak - with clutch service winners. Flipkens, though, was in full flow after overturning a 0-3 deficit in the tiebreak with a series of brilliant backhand volleys, and kept the pressure on - and facing her third set point, Tsurenko would double fault for a third time.

An equally tightly contested second set saw Tsurenko throw caution to the wind as momentum seesawed back and forth. The 30-year-old resolutely sought to take the net away from Flipkens, even committing to a serve-and-volley strategy throughout - with mixed results.

In a remarkably similar pattern to the first set, after an opening exchange of breaks it was Tsurenko who moved ahead on the scoreboard first - breaking for 5-3, thanks not to her net play but the same aggression and improvisation coming through in her groundstrokes and passes. But serving for the set, Tsurenko's forecourt ventures had more of a kamikaze effect than a swashbuckling one: the four-time WTA titlist attempted it on almost every point, and each time found herself easy picking for Flipkens, who broke back as Tsurenko sent a smash over the baseline.

At 5-5, Tsurenko continued to stick with a losing tactic: by now, Flipkens was ready and waiting for the net-rushes, and was more than equal to the task of hitting an aggressive return and swarming the net herself. A fine lob captured another break - and then, as if to rub salt into the wound, the 33-year-old would seal victory on her third match point with an elegant serve-and-volley of her own.

Flipkens' bid to reach a third final in 's-Hertogenbosch will continue in the quarterfinals against either compatriot and No.9 seed Alison Van Uytvanck or qualifier Elena Rybakina. A match against Van Uytvanck would be especially interesting - not only because the pair are good friends but because Flipkens sometimes takes an ad hoc on-court coaching role when the Budapest champion's own coach is unable to travel. "It will be funny because we know each other so well," laughed Flipkens. "If we play, I just hope we have a good match and the best one will win - it's obviously good for Belgian tennis too, if one of us two is going to be in the semis."

Flipkens is less familiar with her other potential opponent, 19-year-old Istanbul quarterfinalist Rybakina. "I don't know her at all," she admitted. "I've heard a lot of positive things about her - young player, hitting the ball really well, really a hard hitter - so I have to be ready to play my game if she allows me to."