LONDON >> Roger Federer was on the decline — or so the thinking went.

He was past 30. Had back problems. Tried experimenting with a larger racket. Was a family man, a father to two sets of twins now. Slid down the rankings. Reached zero Grand Slam finals over the past two years. Started losing before the quarterfinals at majors, including in 2013’s second round at the All England Club, of all places, to a guy ranked 116th.

Look at him now. Federer moved one victory away from a record eighth Wimbledon championship and 18th Grand Slam title overall by reaching Sunday’s final, where he will face Novak Djokovic.

Federer was asked how much it would mean to add to his trophy collection.

“A lot,” said Federer, who turns 33 next month and would be the oldest Wimbledon winner in at least a half-century. “I know I don’t have 10 left, so I’ll try to enjoy it as much as I can.”

Could he have imagined 12 months ago, after his startlingly early exit, being back in this year’s final?

“I wasn’t sure,” Federer replied. “I hoped.”

After so much buzz about the rise of a new generation to challenge the supremacy of tennis’ “Big 4,” — a quartet, including Rafael Nadal and Andy Murray, that will have won 36 of the past 38 Slams — Federer and Djokovic turned aside up-and-comers in Friday’s semifinals.

Djokovic, the 2011 champion, went first on Centre Court, overcoming dips in his play to beat 11th-seeded Grigor Dimitrov of Bulgaria 6-4, 3-6, 7-6 (2), 7-6 (7) and reach his third final at Wimbledon and 12th in the past 16 majors.

Federer, tied with Pete Sampras and William Renshaw with seven Wimbledon titles, followed with a 6-4, 6-4, 6-4 victory over 11th-seeded Milos Raonic of Canada. Returning serves that topped 130 mph (210 kph), Federer broke Raonic once in each set and took 61 of 80 points on his own serve.

“Just seeing Roger around, seeing his persona, his aura — you know that a lot of people could have, and have, written him off in a lot of ways,” Raonic said, “(but) you knew this was very (possible) for him.”

Dimitrov (who beat defending champion Murray in the quarterfinals) and Raonic (who beat the man who beat Nadal in the fourth round) are 23 and were making their debuts in a Slam semifinal. Federer was in his 35th; six-time major champion Djokovic was in his 23rd.

It was sunny, 77 degrees (25 Celsius) and windy, and Djokovic and Dimitrov found themselves slip-sliding around the worn court, especially along swaths of brown dirt. One of their many lengthy, entertaining exchanges ended with both face-down on the turf.

Djokovic appeared ready to run away with a win, one point from leading by a set and two breaks. But Dimitrov, cheered on by girlfriend Maria Sharapova, hit an ace to erase a break point and reeled off five consecutive games to grab the second set.

For Djokovic was volleying poorly — something that surely bothered one of his coaches, three-time Wimbledon champion Boris Becker — and generally struggling to find his strokes. After one botched forehand, Djokovic threw his racket end-over-end in the air and caught it.

“It was a roller coaster,” Becker said of his man’s up-and-down performance. “It doesn’t have to be pretty and perfect all the time. You have to play perfect when it matters most.”

Djokovic did. Dimitrov did not, faltering at the end of the last two sets. In the third, his one-handed backhand accounted for three mistakes in the tiebreaker, and he also double-faulted.

In the fourth, Dimitrov wasted four set points, including three in the tiebreaker, which he led 6-3, before losing six of the last seven points.

“I probably won’t get an hour of sleep,” Dimitrov said.

What keeps Djokovic awake at night is that he lost his past three major finals, and five of his past six.

Sunday’s final will be his 35th match against Federer, who leads 18-16. But it’s only their second major final; the other was at the 2007 U.S. Open, won by Federer.

“My game’s back where I hoped it would be,” said Federer, who lost in the fourth round or earlier at four of the previous five majors but has dropped one set this fortnight.

“Things were difficult all of last year, most of the year, so I’m happy I worked hard off the court to get myself back into shape and back into contention.”