LONDON — Perpetual rain, the changing of the guard, double-decker buses, fish, chips, and Roger Federer in the Wimbledon final.

Quintessential London was safe and sound Friday afternoon when Federer, the Swiss master whose initials are embedded in the AELTC’s emerald turf, knocked down world No. 1 Novak Djokovic, 6-3, 3-6, 6-4, 6-3, to reach the Wimbledon final for the eighth time.

Federer got the job done again with his trademark fluidity, consistency, and near-flawless ground game, but what tied it all together was his unusually strong service game, with which he conjured 12 aces (to Djokovic’s nine) as well as a 72 percent success rate on second service points — an important 15 percent more wiggle room than the crafty Djokovic. That bit of underlying mettle to Federer’s game allowed him to be more aggressive against the tournament favorite.

“We did a lot of first-strike tennis — a lot of service winners out there,’’ said Federer, who broke Djokovic in the sixth game for a 4-2 lead in the first set. “That obviously changes momentum of the match, doesn’t make it maybe as physical. It’s more explosive, maybe a touch unpredictable.’’

Federer, with a chance to win here Sunday for a seventh time after a two-year hiatus, will face the UK’s Andy Murray at Centre Court. Murray later Friday became the first Brit in 74 years to reach the final with his four-set win over Jo-Wilfried Tsonga.

“I was able to be very aggressive, particularly once I did get into the third set where I thought we both played our very best,’’ noted Federer, again stressing how important it was for him to hold on shot and serve. “Now looking back, that was obviously the key to the match.’’

If Federer wins Sunday, he will have not only dethroned last year’s champ in Djokovic, he will slip ahead of the sweet-swinging Serb for No. 1 in the world rankings.

“You know, life goes on,’’ said a somewhat laconic Djokovic. “This is sport. I have to move on.’’

Later, when asked about the potential of Federer moving ahead of him in the rankings, Djokovic added, “Look, if he wins and becomes No. 1 it’s going to be well-deserved. He’s played fantastic this year. He’s been so consistent. If he wins, he wins. There’s nothing I can do about it. The best player will win this tournament. I’m out.’’

Ever precise, a forensic scientist with the racket as his microscope, Federer found the first clue of victory in the sixth game of the opening set, breaking Djokovic to gain the 4-2 lead. Djokovic appeared in control at 30-0, but fell into big trouble when he slipped on a net approach, setting up a break point. With only 17 minutes gone, Federer had the break, Djokovic firing a baseline forehand high into the net. It was one of Djokovic’s 21 unforced errors — to Federer’s mere 10.

Two games later, Federer pocketed the first set, 6-3, with a love game. For a 30-year-old, one known for his on-court thinking and precision more than his power, Federer played with the energy of a tour rookie.

“Is he ready to turn 21 or 31?’’ kidded John McEnroe, commenting on the BBC.

And if Federer had cheated father time, Djokovic’s performance belied conventional wisdom.

“It seemed [Djokovic] almost didn’t want to be out there in the end,’’ said McEnroe.

Before disappearing, Djokovic threatened to make a real battle of it by winning the second set, opening with a win on serve and then promptly breaking Federer to 2-0. It was the rare game in which Federer’s serve broke down, allowing Djokovic a possible mental edge.

But it really unraveled in the third set for Djokovic in the 10th game, when Federer broke him a second time to clinch the set, 6-4. Federer dramatically held serve in the previous game, tying together a trio of unreturned serves to hold at 5-4, and then salted away the set on the break, in large part because Djokovic botched an overhead slam to fall behind, 15-40.

The energy was drained from Djokovic. In the fourth, Federer broke his service in the second game, then remained flawless on serve. Fittingly, the match ended with Federer on serve, Djokovic unable to return either of his final two offerings.

“He served really well,’’ acknowledged Djokovic. “I think high percentage of first serves and really good precision and he was aggressive on his second, as well. And I think what I did bad and wrong today was my first shot after the serve.  You know, I missed a lot of those, I didn’t move as fast as I was supposed to, and I didn’t, you know, get on the ball.’’

Serena going for five

Serena Williams on Saturday will try to win her fifth Wimbledon title, facing Poland’s Agnieszka Radwanska in the only singles match on Centre Court.

Williams, who quickly dismissed Victoria Azarenka in the semis, has not won a Slam since her triumph here in 2010, having missed a year because of a foot injury and a life-threatening blood clot in her lungs.

“I have to go out there and win,’’ said Williams, who will go for her fifth doubles crown when she teams up with her sister, Venus, in the final Saturday against Andrea Hlavackova and Lucie Hradecka. “Agnieszka has had a better year than I have.  She’s been way more consistent than me.  She’s done really well, so she’s ranked higher than me.  She deserves to be. I have to go out there and fight for this. This is by no means going to be easy. Never, ever do I underestimate any opponent. She’s out there to try to do her best.’’

Meanwhile, Radwanska was not available to the media because she has a cold.

“I have picked up an upper-respiratory illness, which is affecting my nose and throat,” Radwanska said in a statement. “I have been playing a lot of matches here in the rain and cold wind, and I haven’t been well for a few days. The most important thing is that I’m feeling good on the court and playing some good tennis, despite not being able to talk much away from the court.”