ANDY Murray will measure himself against one of the best of the next generation in the fourth round of the French Open.

The world No 1 might have expected to play John Isner in a repeat of last year's last-16 clash but instead will face 21-year-old Karen Khachanov of Russia.

Since Murray and Novak Djokovic rose to the top of the game more than a decade ago, the wait has gone on for a new generation to really make its mark.

The signs are that the time has finally arrived, with 20-year-old Alexander Zverev breaking into the top ten and the likes of Nick Kyrgios, Borna Coric and now Khachanov rising up the ranks.

Murray said of today's opponent: "I have never played a match against him but I practised with him before he got on to the tour when he was like 350 (in the rankings) and he was really good. He's a big, strong guy, generates a lot of power. He's also got a big serve."

Khachanov, born in Moscow but based in Barcelona, is through to the last 16 at a slam for the first time.

After beating Tomas Berdych in round two, he bounced back well from losing the third set to Isner to win 7-6, 6-3, 6-7, 7-6 in a match carried over from Saturday evening.

Standing 6ft 6in and with a swagger to match, Khachanov is part of a new breed of very tall but athletic players and is looking forward to having a crack at the Briton.

He said: "I think that is what we are looking for, to play on the big arenas like here, centre court, and to play against the world No 1. I'm really looking forward to it.

"I think it's going to be a good match and good experience for me. I'm in the fourth round and I will try to prepare and to do my best."

A Real Madrid fan, Khachanov prepared for the resumption of his match against Isner by watching the Champions League final. He is also a keen chess player.

He said: "When I was young, like from ten to 12, I was having chess classes, so I like to play chess in my free time. It's one of my hobbies. I think it helps maybe."

The ATP are holding an end-of-season Next Gen tournament for the first time in November as a showcase for the best eight players aged under 21.

Zverev looks uncatchable in first place and Khachanov, who sits sixth, has been inspired by the German's achievements.

He said: "I already congratulated him with past results. I think it motivates us to work even harder. I'm seeing it in the other young guys.

"We are looking to each other and support each other. It helps us, gives us extra motivation and encourages us."

While Khachanov is through to the last 16 at a slam for the first time, it is seven years and 25 tournaments since Murray failed to at least make the fourth round.

His expectations on arriving in Paris were rather different to normal, after a poor run of form on the clay, but he looked much more like his usual self in a straight-sets win over Juan Martin del Potro on Saturday.

"I believe in myself, so even when things aren't going well, I believe I can turn it around," said the 30-year-old Scot.

"It's not easy but, if you do the right things in practice and trust it, it's going to come. The five-set format has definitely helped, so I have maybe not been as anxious going into some of the matches because I know there is some time to turn it around.

"But mentally I feel pretty good just now. I'm working things out while I'm playing the matches and that's a really important part of my game."