Roger Federer and Novak Djokovic will renew their rivalry with a 50th meeting when they do battle in the Australian Open semi-finals.
The all-time greats have been on contrasting runs in Melbourne, where seven-time champion Djokovic will enter their clash on Thursday as favourite.
But Federer cannot be written off in the semi-final encounter most were hoping for once the draw was made.
We take a closer look at the pair ahead of the showdown.
Form and results
For the first time in his career, Federer has reached a grand slam semi-final without facing a top-40 player, but the Swiss 20-time grand slam champion has made hard work of his run. He was tested by John Millman and Tennys Sandgren, saving an incredible seven match points against the latter. Federer appeared to be battling injury during the clash against the American world number 100, but was later hopeful it was "just pain and problems" amid worries over his groin.
R1: bt Johnson 6-3 6-2 6-2
R2: bt Krajinovic 6-1 6-4 6-1
R3: bt Millman 4-6 7-6 (7-2) 6-4 4-6 7-6 (10-8)
R4: bt Fucsovics 4-6 6-1 6-2 6-2
QF: bt Sandgren 6-3 2-6 2-6 7-6 (10-8) 6-3
Djokovic, meanwhile, has been relatively untroubled since a brief hiccup in the opening round against Jan-Lennard Struff. Having been particularly pleased with his serve, the Serbian star has dominated, dropping just one set. Djokovic has won 84 per cent of his first-serve points, which is behind only Ivo Karlovic and Thiago Monteiro – who played two and one matches at the tournament respectively.
R1: bt Struff 7-6 (7-5) 6-2 2-6 6-1
R2: bt Ito 6-1 6-4 6-2
R3: bt Nishioka 6-3 6-2 6-2
R4: bt Schwartzman  6-3 6-4 6-4
QF: bt Raonic  6-4 6-3 7-6 (7-1)
Djokovic is the favourite in the 50th meeting between the all-time greats, his form and condition seemingly giving him the upper-hand against Federer. He holds a 26-23 record over the 38-year-old, but was beaten in straight sets when they met at the ATP Finals late last year. At grand slams, Djokovic holds a 10-6 record, while he has won three of their four Australian Open meetings. Djokovic is unstoppable when he gets to this stage in Melbourne – he has won the tournament every time he has reached the semi-finals.
Whoever secures a spot in the final will face Rafael Nadal, Dominic Thiem, Alexander Zverev or Stan Wawrinka.
What they said
Federer: "I think conditions suit us well here. Start the year strong, probably something to do with court speed, feeling comfortable down here."
Djokovic: "Roger is Roger. You know that he's always going to play on such a high level, regardless of the surface. He loves to play these kinds of matches, big rivalries, semis, finals of grand slams."