It's Grand Slam number 20 for the greatest.

The greatest just got even greater.

For the 20th time in his career, Roger Federer has lifted Grand Slam silverware, defeating Croatia’s Marin Cilic to win his sixth Australian Open title.

The 36-year-old came into the tournament as defending champion and second seed, but once Rafael Nadal was forced into a quarter final retirement, all eyes turned to Federer, as he marched through to his 30th slam final, where he would face Marin Cilic.

When the pair met in last year’s Wimbledon final, Federer cruised to a straight sets win, and despite this one lasting the distance, Federer never looked in trouble against the former US Open winner.

Twice he led, taking the first set 6-2 and the third 6-3, but on each occasion Cilic fired back to level, breaking Federer in game eight of the fourth, before holding his own serve to take the game to a deciding fifth.

After a back and forth opening game in the decider, Federer held his nerve and his serve, before breaking Cilic in the second, and a further break allowed him to comfortably see out victory, a result which only cemented his legacy as the greatest men’s tennis player ever. In the end, it finished 6-2 6-7(5) 6-3 3-6 6-1.

His ability to dig in and win five set battles beyond his mid 30s - as he has showed in each of his last two Australian titles – indicates his current total of 20 Grand Slam titles may continue to grow. He’s never liked the clay, but after winning Wimbledon in such emphatic fashion last year, and his main rivals all struggling with injury, Grand Slam number 21 is certainly a possibility later this year.

If he doesn’t add to the 20 before hanging up his racket, then so be it. After a four and a half year spell when it looked like he was meandering towards retirement, his three Grand Slams in the last 12 months have been a further reminder to the challengers that there’s still only one sheriff in town.