Just where does it end for the great Roger Federer?

Number 20 once seemed so improbable for the Swiss great, but that milestone was accomplished in Melbourne on Sunday. Federer overcame Marin Cilic 6-2 6-7 (5-7) 6-3 3-6 6-1 in a thrilling Australian Open final on Rod Laver Arena, winning his 20th major title. It also marked his record-equalling sixth Melbourne crown, matching Roy Emerson and Novak Djokovic.

So, just where does it stop for the greatest player of all-time? Federer, 36, is still in top form, his title in Melbourne adding to the two grand slams he won last year. After undergoing surgery on his knee in 2016, the recent feats appeared so unlikely for the Swiss great. For those few who doubted him, he has silenced those critics.

While he may skip the French Open again, Federer is still capable of winning Wimbledon and the US Open.

With the rest of the 'Big Four' – Rafael Nadal, Novak Djokovic and Andy Murray – struggling with injuries, just who will stop Federer? The 'Next Gen' is yet to step up, with the tennis world waiting for the likes of Alexander Zverev and Nick Kyrgios to live up to their potential, particularly in majors.

Federer again delivered an emotional speech post-match to an adoring Rod Laver Arena faithful. The Swiss great was reduced to tears as he thanked fans, and – unlike he usually does – there was no mention of next year.

Speaking to Channel 7 afterwards, Federer described his speech as a "mess", saying he was simply relieved to claim the title, and discussing some of his potential plans for 2019.

Up to 20 grand slam titles, Federer is now four clear of Nadal and eight ahead of Djokovic on that list. In his current form – he did not drop a set on his way to the final in Melbourne – he will add to that number.

There are no signs Federer has plans to stop just yet, and 20 is surely not where it ends, at least not unless the Swiss maestro decides his time is up.