Roger Federer dug deep, coming back from a break down in the fifth and deciding set to beat Rafael Nadal 6-4, 3-6, 6-1, 3-6, 6-3 in the men's singles final of the 2017 Australian Open on Sunday, clinching his 18th Grand Slam title in the process. The two greats pushed each other to the brink, producing another great chapter in their long-running rivalry.