Belinda Bencic looks like a future world No. 1. Ever since her breakthrough at the 2014 US Open, she has demonstrated an innate ability to handle pressure situations, and a greater capacity to cope with setbacks than most of the other rising stars on the WTA tour.

Her Australian Open fourth-round encounter with Maria Sharapova is set to be one of her biggest challenges yet. While the Russian still appears a bit short of match practice, she is a formidable opponent who will test every aspect of Bencic’s game. And it is the 18-year-old’s serve that will be most vulnerable, since if she drops it short, Sharapova will pounce on it and power it back past her time and again. If such a pattern develops, the five-time Grand Slam champion could dominate.

But you write Bencic off at your peril. The Swiss teenager takes the ball early, has a great variety of shots, and can adapt her strategy to great effect if her original game plan is not working because she reads the game so well. If both players play well, it will be a fascinating match to watch, and the prize for the winner is likely to be a quarterfinal against Serena Williams – a clash Sharapova would dread and Bencic might relish, having defeated Serena last summer in Toronto. If the Swiss beats Sharapova, it is impossible to look beyond a probable quarterfinal with Serena. Win that, and Bencic will believe she can take home her first Grand Slam title, aged just 18.

So if Bencic makes it to No. 1 in a few years, who will be her No. 2? It could be someone experienced like Sharapova, Victoria Azarenka, or Agnieszka Radwanska, but there is a very good chance it could be another youngster. Two of the leading candidates, Simona Halep and Garbine Muguruza, suffered surprising losses in Melbourne this week, but they remain firmly in the running. However, they may face strong competition from a woman who is still in contention for the 2016 Australian Open title: Madison Keys.

Like Bencic, Keys has long been tipped for greatness, and last year was her best yet. She reached the semifinal in Melbourne and the quarterfinal at Wimbledon, losing to superior opponents – Serena Williams and Agnieszka Radwanska – on both occasions. She also made the fourth round at the US Open and the third round at Roland Garros, which aptly demonstrates her ability to perform well in Grand Slams. If she is to reach the very top of the women’s game, however, she will have to improve her performances in lesser tournaments, where she appears to struggle for motivation.

Before any of that is tested, Keys has a great opportunity to reach at least the semifinal of this year’s Australian Open. Despite impressive wins over Halep and Alize Cornet, fourth-round opponent Shuai Zhang should not pose many problems for Keys, particularly if the American imposes her big-hitting game early in the match and races into a lead. This would force the Japanese journeywoman to deal with a deficit for the first time in the tournament, and, given how long she had to wait for her first Grand Slam match win, she could easily crumble.

Johanna Konta or Ekaterina Makarova would be Keys’ opponent in the last eight and, while either could be difficult to beat, both are players who the American should beat, particularly if she wants to become one of the best in the world. When Keys wins a match, she invariably overpowers her opponent, and she is definitely capable of doing that against Zhang and then either Konta or Makarova. However, she would find this much more difficult to do in a likely semifinal against the in-form Victoria Azarenka, who has successfully gone toe-to-toe with Serena in the past and is yet to drop a set in 2016. If Keys does reach the semifinal and then defeat Azarenka, it will give her career a huge boost, whatever happens in the final.

The progress of players like Bencic and Keys is one of the most exciting things happening in the tennis world right now. While men’s tennis appears locked in a never-ending cycle of the same players fighting for all the big titles, talented youngsters are beating established names everywhere you look in the women’s game. The impressive run of Daria Gavrilova is a prime example. She has gone from world No. 233 at the end of 2014 to beating Petra Kvitova in the Australian Open at the start of 2016. And Bencic, Keys, and Gavrilova are joined in the fourth round by four other players under the age of 25. What a time to be a fan of women’s tennis!