Jelena Ostapenko produced arguably the best performance of her career to beat two-time Wimbledon champion Petra Kvitova 6-4 4-6 6-3 in the second round of the Aegon Classic in Birmingham and set up a fascinating quarterfinal clash with the in-form Madison Keys.

The Latvian, 19, showed a maturity beyond her years as she consistently produced her best tennis at the most crucial times in the match, which is often a sign of a promising young talent. The break point stats illustrate this perfectly, as Ostapenko saved an incredible nine break points out of 12 faced and converted five of the eight she earned on Kvitova’s serve. Despite that impressive conversion rate, she thought she could have done better. Ostapenko said, ‘I was just trying to stay consistent and play my game. I had some break points that I didn't use. Grass court tennis can be difficult because the bounce is sometimes not very good.’

While Kvitova was understandably disappointed to lose the match, she recognized that her opponent played well and was also fairly happy with her own level of performance. She said, ‘I think I showed good tennis today. I don't know that I did anything wrong. She was just really going forward. I think she played better on the key points in the third set, and she returned very well. It was difficult to put pressure on her, and she was pushing me a lot.’

Most aspects of Ostapenko’s game were working well today, but one element in particular stood out:  her serve. She fired down eight aces during the match, and, on most of the 12 occasions when she faced a break point, she produced a huge serve to save it. This aspect of her game, along with her excellent groundstrokes, has helped Ostapenko realize that she can be a dangerous player on grass. She said, ‘I’ve done well on grass since juniors. I think it’s my favorite surface, so I'm looking forward to two more tournaments. I have a good serve and a good backhand and forehand, so I think my game is good for grass.’

Ostapenko will arguably have to play even better on grass in her quarterfinal match, when she will go up against another specialist on the surface in the form of Madison Keys. The American has been in scintillating form ever since her run to the semifinal in Rome last month, and she decimated second-round opponent Tamira Paszek 6-1 6-3 in just 58 minutes today. Like Ostapenko, Keys served very well. She got 74% of her first serves in the court and sent down eight aces – the same number as the Latvian. She also only produced one double fault to Ostapenko’s six, which is a statistic that, if repeated, could make a crucial difference when they meet. Keys also converted four of her eight break points against Paszek.

Keys will deservedly be regarded as the favorite in the quarterfinal, which will be the first time they have played each other, particularly since she has more experience in top-level tennis, but Ostapenko’s chances should not be discounted. She has just beaten one of the best players in the world on her favorite surface – something she knew well. Ostapenko said, ‘On grass, she's one of the most dangerous opponents because she won Wimbledon twice. I was happy to win today.’ And she also won the Wimbledon Girls’ Singles title in 2014, which justifies her confidence on grass. So all things considered, the precocious Latvian is capable of springing another upset against Keys. Whatever happens in that match, today in Birmingham was definitely her day to savor.