Magnificent Roger Federer reaches final after Chung Hyeon is forced to retire with blisters

The defending champion - chasing his sixth title in Melbourne at the age of 36 - broke Chung's serve three times on Rod Laver Arena without breaking sweat in the first set as the South Korean player was utterly dismantled by the Swiss player's stunning all-court game.

He will face Croatian sixth seed Marin Cilic in the final on Sunday in a repeat of last year's Wimbledon final that Federer won in straight sets.

World number 58 Chung was trailing 5-2 in the second set when he retired a game after receiving treatment for blisters with Federer on the cusp of a two-set lead after only one hours and two minutes on court.

Federer will chase a 20th major in his 30th Grand Slam final since 2003.

"I thought the first set was kind of normal, I couldn't tell what was going on with my opponent," said Federer. .

"In the second set, I could feel he was getting a bit slower, fighting with the blister. It hurts a lot.

"It's better to stop, that's why this one feels bittersweet. Credit to him for trying so hard again today."

In what was their first meeting on tour, the outclassed Chung could only hit six winners with 19-times Grand Slam winner Federer unearthing 24 winners in a match that felt more like a training exercise.

When Chung held serve to make it 1-1 in the second set a huge cheer went up from the Australia Day crowd who had hoped to witness a classic battle of the generations.

But the bespectacled 21-year-old simply had no answer to Federer's masterclass.

Federer broke for 3-1 with a dipping backhand pass and when Chung needed treatment on his foot blisters at 1-4 his hopes of becoming the first South Korean to reach a grand slam final looked completely hopeless.

Chung managed to win one more game but threw in the towel as the match ended on a low note for South Korea, but for Federer there is only highlights as he reaches his latest Grand final without dropping a set.

It was left to Chung's agent Stuart Duguid to explain his client's ailment as "blister under blister under blister."

It was "red raw" he told reporters, and pain killing injections had provided no relief.

Chung made clear he was not interested in grinding through, however, fearing fans would be disaffected by a poor show.

"Many things come together because I retired in (the) semis," he said.

"But I think I did (the) right thing. If I play (a) bad thing on the court, it's not good for the fans and audience as well.

"I'm happy to be able to make the semis in a grand slam. I want to be stronger next year."

Chung can certainly hope to fulfil those expectations after a giddy fortnight that included demolishing an injury-hampered Djokovic in three sets and a brilliant win over fourth seed Alexander Zverev, who many had regarded as the strongest young contender in the draw.

Chung said he had already attained some of his goals by becoming South Korea's top ranked player and achieving his best showing in a grand slam.

"I really didn't know I'm going to make it in semis," Chung added. "Next goal is I want to finish the season without injury."