Milos Raonic is playing at the top of his game.

In a month that saw him defeat Roger Federer, he just upset the #4 player in the world in a grand slam tournament. Raonic has defeated Stan Wawrinka, the winner of the 2014 Australian Open and last year’s French Open.

The win represents Raonic’s first win against a top-5 player in a Grand Slam. You can call it the biggest win of his career.

Raonic now has wins over Rafael Nadal, Federer, and Wawrinka in his career. Prior to this win, Raonic had only ever beaten a top-10 player once in a Grand Slam.

Raonic, who had cruised through the first three rounds of the Aussie Open without dropping a set, defeated Wawrinka in a five-set thriller (6-4, 6-3, 5-7, 4-6, 6-3).

It appears that Raonic has found another level in his game. The big-serving Canadian that seemed a bit awkward in other parts of his game, appears to be a thing of the past.

The return game, net play, tactics, defending, mental toughness … Raonic seems to have found another level

— Mark Masters (@markhmasters) January 25, 2016

Raonic used to live and die with his serve. Not anymore. He was able to break Wawrinka’s serve three times in the second set.

Milos Raonic hits a beautiful backhand volley from his shoetops. He's moving forward so well, picking his spots.

— Tom Perrotta (@TomPerrotta) January 25, 2016

Missile Raonic continues to play the best tennis I have seen from him ever on return game about to be 2 set to the good vs Stanimal

— Brad Gilbert (@bgtennisnation) January 25, 2016

If Raonic keeps this up, he can beat anyone in the world.

Next up for Milos is Gael Monfils, the 23rd seed from France. Raonic is 0-2 in his career versus Monfils, though their last game was three years ago and the big Canadian should be considered the favourite.

Should Raonic beat Monfils, he will face one of Andy Murray (#2), David Ferrer (#8), John Isner (#10), and Bernard Tomic (#16).