Roger Federer booked his place in Sunday's Australian Open final with Marin Cilic, after opponent Hyeon Chung retired hurt in the second set, visibly struggling with blistering issues on his feet with the South Korean serving to save the set at 2-5, 1-6 down at Melbourne Park.

The Swiss faces the Croat in a repeat of last summer's Wimbledon final, vying for his sixth title in Victoria and what could be a remarkable 20th grand slam title.

Federer blast to early lead

With the defending champion having shown mere fleeting signs of nerves throughout the fortnight, Federer blasted his way to a 4-1 advantage in the opener.

Chung on the other hand, much like Kyle Edmund in Thursday's semi was showing visible signs of stage fright, with the Korean being easily dampened by the Swiss across the net.

At 5-1 up, the unseeded Asian showed signs of life after holding Federer up in his early rampage on Rod Laver. Its was however ultimately academic, as the five-time champion in Victoria eased to the opening set 6-1 in just 33 minutes.

After holding his opening game, the procession then continued as Federer again blazed out to a 4-1 lead, with Chung becoming somewhat a passenger in proceedings in a hurry.

The veteran Swiss even had time to engage in a verbal jousting match with chair umpire Carlos Ramos, with Federer wronged over a questionable call during a point.

His opponent meanwhile - again like his defeated British counterpart Edmund - was showing signs of the exertions of his efforts earlier in the tournament, as the South Korean's mind and body began to unravel with an issue of blisters becoming a literal thorn in Chung.

Chung forced to call time

Play resumed with Chung taking just his third game of the contest, before the Federer express again picked up pace, through a combination of again forcing errors, and the sheer power of the Swiss' backhand.

Chung served at 2-5 down to save the second set, but after his ability and in particular movement on the court had been visibly affected at 30-30, Chung moved to the net and was forced the cut the match short, retiring to shake hands with Federer at the net.

The issue of his feet was clearly a bigger factor than had been first thought - perhaps throughout the match that had played out - but his retirement was still something of a shock for the watching and paying patrons in Melbourne.

All that remained was for Federer to comiserate with his opponent, as the Swiss took his place in Sunday's showpiece final with Cilic, in a battle of number two versus number six in the world this weekend.