Serbia's Djokovic, chasing records on multiple fronts, left it late to book his place in round four, beating Stan Wawrinka 6-3 6-1 7-6(5) just before Wimbledon's 11pm curfew.
Spain's world number Alcaraz is a round behind because of this week's rain but picked up speed with a 6-4 7-6(2) 6-3 victory against Frenchman Alexandre Muller.
Women's top seed Iga Swiatek continued her serene progress with a third successive straight sets win -- this time against Croatia's Petra Martic 6-2 7-5.
Second seed Aryna Sabalenka suffered a scare though before hitting back to beat Varvara Gracheva of France 2-6 7-5 6-2.
For British fans, at least, day five fell flat with Murray unable to finish off fifth seed Stefanos Tsitsipas.
The 36-year-old had led two sets to one after Thursday's late night action and there was a wave of Pimms-fuelled optimism that he could finish the job on Saturday.
Tsitsipas had other ideas though and silenced the partisan Centre Court crowd to prevail 7-6(3) 6-7(2) 4-6 7-6(3) 6-4 on the 10th anniversary of Murray's first Wimbledon crown.
MURRAY DISAPPOINTED
"I'm obviously very disappointed just now," the Scot told reporters as he processed the loss.
"Yeah, obviously you never know how many opportunities you're going to get to play here. The defeats maybe feel a bit tougher. But, to be honest, every year that Wimbledon's not gone how I would like, it's been hard."
Shortly before Murray's demise, Britain's 12th seed Cameron Norrie was bundled out in the second round by in-form American Christopher Eubanks -- a player who dabbles with commentating and who is making his Wimbledon debut.
And to really rub salt into the wounds, home wildcard Liam Broady, who on Thursday stunned fourth seed Casper Ruud, lost to mercurial Canadian Denis Shapovalov 4-6 6-2 7-5 7-5.
Britain's only singles survivor is Katie Boulter who faces women's champion Elena Rybakina on Saturday.
Broady at least had the honour of being Britain's best-performing male player this year, although he did not take too much comfort from that fact.
"Kind of makes it worse that we've all lost on the same day, as well. Probably would have felt a bit better if we'd staggered what days we lost on, whereas now it's a bit of a Debbie Downer, isn't it?" he told reporters.
Alcaraz mixed power-hitting, fearsome returning and delicate drop shots to beat Muller, declaring afterwards that he belonged on the "really beautiful court" and hoped to play Djokovic in the final on Sunday week.
"I feel like I'm ready to play more matches, to play more great matches on that court," U.S. Open champion Alcaraz said after reaching the third round where he will play Chile's Nicolas Jarry on Saturday.
"It would be amazing to play a final here in Wimbledon. Even better if is against Novak obviously."
RECORD TIEBREAK
A hectic day in the women's draw ended with a shock under the Court One roof as fifth seed Caroline Garcia was outlasted by 32nd seed Marie Bouzkova 7-6(0) 4-6 7-5.
Earlier Lesia Tsurenko win a dramatic match against Ana Bogdan after saving five match points and winning a 38-point tiebreak, the longest in women's singles Grand Slam history.
The Ukrainian and her fellow unseeded opponent from Romania split the opening two sets but an incredible battle unfolded at 6-6 as Tsurenko dug deep to win the breaker 20-8.
Tunisian Ons Jabeur made quick work of Chinese qualifier Bai Zhuoxuan with a 6-1 6-1 win in 45 minutes while twice former champion Petra Kvitova cruised into the third round after the ninth seed beat Belarusian Aliaksandra Sasnovich 6-2 6-2.
She was joined by Ukraine's Marta Kostyuk whose Spanish opponent Paula Badosa retired with a back injury. Badosa, the 25-year-old girlfriend of Tsitsipas, also pulled out of the mixed doubles in which she was scheduled to play alongside him.
Last year's quarter-finalist Jannik Sinner of Italy, seeded eighth, recovered from a poor start to beat Frenchman Quentin Halys 3-6 6-2 6-3 6-4, while Russian third seed Daniil Medvedev downed Adrian Mannarino 6-3 6-3 7-6(5).
