On Friday, Madison Keys and Coco Vandeweghe kept up their stunning form to reach the semifinal stage of the Aegon Classic in Birmingham and increase the likelihood of playing each other for the first time ever in Sunday’s final.

Both were impressive today, but in different ways. Keys, 21, drew on all of her experience from three years of top-level tennis to beat 19-year-old rising star Jelena Ostapenko 6-7 6-4 6-2 in a high-quality encounter, while Vandeweghe powered to straight-sets wins over Christina McHale and Yanina Wickmayer, despite only having a couple of hours rest between them, as the tournament played catch-up after rain plagued the first four days.

The schedule was kinder to Keys, who was the only semifinalist who did not have to play two matches today. She said, ‘Going in knowing I only had one match was a huge thing. I'm sure everyone else was not super happy with that. It just happened to work out that way. I was just really lucky.’ Vandeweghe certainly thought so. She said, ‘Keys has had the luckiest time ever. We're friends, so I said to her today, “Jesus, you're the only one that finished every single day and doesn't have to play two matches. You're so lucky.” She actually gave me a swat. That's how sympathetic she was. She's been pretty lucky, and I told her so.’

If Keys goes on to win the Aegon Classic, she can be thankful that fortune favored her this week. But, luck or no luck, she is in the semifinals on merit. After she thrashed her first two opponents, Timea Babos and Tamira Paszek, she was given a real test of temperament by Ostapenko and passed with flying colors. Keys said she was worried Ostapenko would maintain the high standard of tennis she produced in the first set and a half for the whole match.

She said, ‘She was playing really well. I tried to change things up a little bit, started taking time away a little bit better, and was maybe a little bit more aggressive. But at the end of the day, if I changed tactics the way that I did, and she kept playing that well and beat me, that would have just been too good. I either had to try something or back up and head to Eastbourne!’

When she went a break down early in the second set, Keys sensibly opted to keep things simple and keep putting the ball back in play in the hope that Ostapenko’s level would eventually drop. She said, ‘That's definitely what you're trying for. You're trying to keep the person out there as long as you can and keep them in longer rallies. Put them in tight situations to see if they can keep their level up. If they do, too good from them. But a lot of times, even if they only slip up for a point or two, you can capitalize on that.’

A couple of years of ago, when Keys herself was 19, she might have lost a match like this by taking too many risks when she fell behind. But she has now learned to handle difficult match situations. She said, ‘I’ve experienced matches where you win a tight first set, the other person plays a little bit better, and you play a bad point here or there, and the wheels kind of fall off. But this year, I've settled into my emotions a little bit more and have been able to play a lot calmer, which I think has helped me make smarter decisions, which in turn maybe makes me look a little bit more mature.’

Claiming the title on Sunday would be the ultimate way for Keys to demonstrate her new-found maturity, but she might have to beat Vandeweghe to achieve it, and the 24-year-old is arguably playing the best tennis of her career right now. Vandeweghe said, ‘I definitely have the confidence. There's no reason I shouldn't as I haven't lost a match yet. That helps in the big moments because it means I'm not panicking.’

Vandeweghe was referring to her grass-court season this year, which so far consists of eight consecutive wins for the loss of just one set. However, she doesn’t believe grass is necessarily her best surface. She said, ‘I've seen the stats of me on grass versus other surfaces. But if you looked at my stats for my best four hard-court tournaments, I think they'd be up there as well.’

The world No. 32 is a lively character on court, whose emotions are often clear for all to see. But it hasn’t always been that way. She said, ‘I haven't always had that. I think it's actually come with my maturity of realizing what I'm comfortable showing on court. It's kind of my B personality. I can be a little bit abrasive sometimes, a little bit confrontational. But if I'm talking to somebody else, it's all in good humor. And it also helps me. It's my cue not to wallow in myself and to focus on outside things, which has always helped me.’

Keys and Vandeweghe are close to reaching the final, but they remain reluctant to look further ahead than their semifinals. Keys plays Carla Suarez Navarro, who completed a rain-delayed three-set win over Andrea Petkovic and then beat defending champion Angelique Kerber 6-4 1-6 7-5, and Vandeweghe faces Barbora Strycova, who is yet to drop a set during the tournament and has beaten Karolina Pliskova, Heather Watson, and Tsvetana Pironkova en route to the last four.

Vandeweghe said, ‘I think all players deserve credit for getting to where they are. They had to beat a seed to get there, so they're obviously doing something right. So you have to take everyone pretty seriously.’ Keys agreed. She said, ‘Everyone who is into the semis is playing well and deserves to be there.’ If Keys and Vandeweghe can beat their challenging semifinal opponents, Sunday’s final promises to be a very entertaining All-American affair.