Melbourne: A ruthless Roger Federer handed wounded Chung Hyeon an old-fashioned schooling before the South Korean quit with blistered feet trailing 6-1, 5-2 in a damp squib of an Australian Open semi-final on Friday.
Federer was detained for only 62 minutes under the Rod Laver Arena roof as he set up a final against Croatia's Marin Cilic who pummelled another young gun, Kyle Edmund, on Thursday.
A business-like Cilic doused the fire of Edmund before crushing the ailing Briton 6-2, 7-6 (7-4), 6-2 to become Croatia's first Australian Open finalist.
Sixth seed Cilic, who won his quarter-final when Rafael Nadal retired hurt in the fifth set, was again ruthless against a reduced opponent, ending 49th-ranked Edmund's dream run after just two hours and 18 minutes.
Federer, the 36-year-old defending champion, swarmed all over the world number 58 from the first game, breaking immediately before repeating the feat twice more to grab the opening set in 33 minutes.
When Chung held serve for 1-1 in the second set, a huge cheer erupted from an Australia Day crowd who had hoped to witness a classic battle of the generations.
But the bespectacled 21-year-old, nicknamed 'the professor', simply had no answer to Federer's firepower.
Federer broke for 3-1 with a dipping backhand pass and when Chung needed treatment on his foot blisters after losing the next game, 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 his movement was clearly affected and he threw in the towel, departing the arena to sympathetic applause with a smattering of boos.
It was a desperately disappointing end to the first meeting between 19-times grand slam champion Federer and the man whose stunning fourth-round victory over six-times Melbourne champion Novak Djokovic made the world sit up and take notice.
"I thought the first set was kind of normal, I couldn't tell what was going on with my opponent," Federer, who looked as stunned as the crowd at the sudden stoppage, said on court.
"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."
Federer, who has reached the final of a grand slam without dropping a set for the sixth time, will be a big favourite to claim his 20th major title on Sunday.
He beat the big-serving sixth seed in last year's Wimbledon final when Cilic also suffered painful blisters to his feet.