This most retro of grand slam tournaments has taken another step back in time, as Roger Federer survived a stirring comeback and five-set challenge against Swiss countryman Stan Wawrinka to take a giant leap into his first Australian Open final since 2010.

At 35 years and 174 days, Federer became the oldest grand slam finalist since 39-year-old Ken Rosewall at the 1974 US Open. The 17th seed will return on Sunday night against either Rafael Nadal or Grigor Dimitrov as the lowest ranked man to contest a Melbourne Park decider since world No.38 Jo-Wilfried Tsonga lost to Novak Djokovic in 2008.

With the Williams sisters – Serena, 35, and Venus, 36 – already booked to contest their first joint Australian final at Melbourne Park since 2003, Federer continues to wave the veteran's flag in the men's draw. Having shared a quiet coffee during the day, there was nothing relaxed, or intimate, about their subsequent catch-up before a ragingly pro-Fed crowd Rod Laver Arena.

"It feels amazing. I never ever thought in my wildest dreams that I'd be coming this far here in Australia and here I am. I have got a couple of days off. It's beautiful. I'm so happy," Federer said after winning 7-5, 6-3, 1-6, 4-6, 6-3 to reach his 28th major final and take his comeback from a six-month break with a knee injury to within one match of a remarkable climax.

He admitted he had been dodging questions about the possibility of a final for the past few rounds, but could discuss it now it had become a reality – and the sentimentalists' dream reunion with Nadal a real possibility. "I'll leave it all out here in Australia and if I can't walk for another five months that's OK," Federer said. "I'll give it all I have."

He had lost his past five Australian Open semi-finals since winning the most recent of his four championships in 2010. Federer's sole grand slam title since then was his 17th, at Wimbledon, back in 2012. And if there was to be one last glorious hurrah, so the thinking has been, it would surely be on the beloved All England Club lawns that have hosted two of his three major finals since.

This, indeed, is well ahead of schedule, although one that was threatened when Federer had to stave off break opportunities in consecutive games early in the fifth set, before grabbing a 4-2 lead with the help of just Wawrinka's second double-fault for the match that came during one particularly shaky, tentative service game against the flow. A standing ovation greeted Federer's next hold of serve. Another followed soon after.

Both players had saved three break points by the time Federer converted one on his first set point, two backhand misses from Wawrinka compounded by another on his forehand side. The fourth seed's frustrations spilled over after the next break, which gave Federer a 4-2 lead in the second set. After netting a backhand, Wawrinka bounced his racquet, then picked it up and calmly broke it into two pieces while waiting for the inevitable code violation warning.

By that stage, the match, too, seemed inexorably headed towards just one result, as Federer raced through the second set in just 31 minutes. Wawrinka then left the court and returned with his right knee taped, as it was in his quarter-final against Tsonga. When the reigning US Open champion returned he was still struggling initially to make an impression on the serve of the senior Swiss – in age and record, but not, currently, ranking – who was moving and mixing up his game beautifully, slicing his backhand effectively, and making the most of his regular but not excessive forays to the net.

Yet, the complexion changed dramatically a couple of games into the third set, when Wawrinka – either resigned, or desperate, or both – started playing more aggressively, taking chances, swinging freely and hard. There was nothing to lose and, indeed, plenty gained. Having ended Federer's run of 20 consecutive service holds and then doubling up for 5-1, the gap was closed in just 26 minutes and in a manner – winning 20 of the last 26 points – that few had seen coming.

Wawrinka had never managed a 6-1 set in the pair's 21 previous meetings, and Federer was caught off-guard by the recovery, broken in the first game of the fourth before he was able to stem the bleeding. By mid-set, Wawrinka's knee was appearing to be slightly more problematic, but his eye was in, and the winners still coming. And coming.

Federer's second serve was vulnerable, and a couple of lovely forehands in the ninth game of the fourth helped Wawrinka to force a fifth. First, though, as his opponent had done an hour earlier, Federer left the court for a medical time-out, a lengthy and uncharacteristic one, citing a "leg thing" that he had felt all week and from the second game of the match.

He was in trouble late in the first five-setter in seven grand slam meetings between the friends and Davis Cup-winning teammates, who shared Olympic doubles gold in Beijing in 2008. And knew it. "I thought that Stan had the upper hand from the baseline… I thought he was reading my serve well. I did feel that he gave me a bit of a cheap break," said Federer, his record against Wawrinka on hardcourt 14-0, and the pace of this one tailor-made for the former No.1's game.

He now has an extended recovery time, and two days off before his sixth Australian Open final, in his 100th match, with the first half of two great champions' super-final tantalisingly booked. "He's an incredible competitor," Federer said of Nadal. "I think both of us thought that we were never going to be potentially playing here in a finals... I think for both of us it's very special, this tournament, already."