US Open PHOTOS: Classic Federer sets up showdown with Djokovic

Five-time champion Roger Federer reached his first US Open final in six years as he flew by fellow Swiss Stan Wawrinka 6-4, 6-3, 6-1 in the semi-finals on Friday.

The second-seeded Federer, in remarkably sublime form at the age of 34, has not dropped a set in his formidable Flushing Meadows run and never let up the pressure on fifth-seeded French Open winner Wawrinka in a 92-minute demolition.

The trouncing set up a delectable one-two showdown in Sunday's final against Australian Open and Wimbledon winner Novak Djokovic, who trails Federer 21-20 head-to-head.

Federer won their last match in the August hardcourt final in Cincinnati, while Djokovic won their last slam encounter in the Wimbledon final.

Federer ill be gunning to add to his record 17 slams haul for the first time since his 2012 Wimbledon triumph.

"It's been a great tournament so far," Federer, who won five straight US crowns from 2004 and was runner-up in 2009, told the Arthur Ashe Stadium crowd.

"I've tried very hard the last six years to get back in another final."

The evergreen Swiss was not broken by Wawrinka as he improved his head-to-head edge to 17-3 while avenging a quarter-finals loss to him this year at Roland Garros.

Wawrinka might have had some trouble adapting to the evening conditions after his previous daytime match in the main stadium, but that was the least of his problems.

"Conditions a little bit different than when I play my match here on Ashe," he said.

"It's a little bit more flying in the night. It's playing really fast. I didn't play my best game.

"But basically it's him, the way he's playing."

Federer improved his match record this year to 51-7 with five titles.

Federer occasionally trotted out his sneak attack, rushing the net on return of second serve to apply immediate pressure. It produced mixed results, but helped set a fast-paced tone that seemed to unsettle Wawrinka.

"He's trying to play really aggressive, really fast," said Wawrinka, 30.

"The way he's playing he's reading better, moving better, so everything is going faster."

Federer has been serving beautifully the entire tournament and he registered 10 aces against Davis Cup team mate Wawrinka.

"I'm serving very well, playing positive tennis, going for my shots and it seems to work," he said. "I'd love it to work just one more time this year."

On high alert after a day of spectacular upsets, world number one Novak Djokovic made sure his name was not added to the list of shocks, crushing defending champion Marin Cilic 6-0, 6-1, 6-2 to reach the US Open final on Friday.

After watching women's world number one Serena Williams and second seed Simona Halep crash out on Arthur Ashe Stadium court, Djokovic came out firing on all cylinders and needed just 85 minutes to bring Cilic's title defence to a shuddering halt.

Djokovic quickly made it clear he would not be would not be joining them at the exit as he ran his record to 14-0 against the ninth-seeded Croat and moved one win away from adding to his 2015 grand slam triumphs at the Australian Open and Wimbledon.

The Serbian world number one will face Federer n the final on Sunday.

"Expectations are always there from myself and from the people around me," said Djokovic, who has one US Open victory on his resume and has now reached the final six times.

"I came here with a wish and a mission, as well, to reach the finals and fight for the trophy.

"So I got myself in that position. It's already a great result. But I want to get that final step on Sunday and get my hands on that trophy."

Cilic entered the contest riding a 12 match win streak on the Flushing Meadows hardcourts but it became clear very early that he would have a difficult time extending it as Djokovic tore through he opening set in just 24 minutes.

The big-hitting Croat, who confirmed later he was carrying a foot injury into the match, held his opening serve in the second but Djokovic had him quickly under pressure again with an early break, charging in front 4-1.

A razor sharp Djokovic, who converted eight of 14 break chances, remained ruthless to the very end, showing the wounded Cilic no mercy.

"Well, I knew that I'm not 100 percent, even the last match I wasn't feeling 100 percent," said Cilic.

"The foot was causing me obviously some trouble with the movement but Novak was able to expose me much more today.

"Even coming before the match and thinking if I'm going to play or not, I decide to play, as it's a grand slam tournament, it's deep in the tournament."