In the Open era, only Bjorn Borg, Pete Sampras and Roger Federer have managed such a streak at the All England Club.
Next up for Djokovic is Thanasi Kokkanikis. "Novak is kind of a brick wall," said the Australian.
Alcaraz, a potential quarter-final opponent for Djokovic, came back from two sets to one down to defeat Germany's Jan-Lennard Struff.
The 19-year-old fired 30 aces and 73 winners in a dazzling display of shot-making to win 4-6, 7-5, 4-6, 7-6 (7/3), 6-4.
"Last year, I played five sets in the first round here as well so this shows how much I like grass," joked Alcaraz.
'Lunch or siesta'
Spain's Alejandro Davidovich Fokina knocked out 2021 semi-finalist Hubert Hurkacz courtesy of the tournament's first final-set 10-point tiebreak.
World number 37 Davidovich Fokina triumphed over the seventh-seeded Pole 7-6 (7/4), 6-4, 5-7, 2-6, 7-6 (10/8) in a match interrupted twice by rain.
"When the rain came at 5-5 in the third set, I didn't know whether to have lunch or take a siesta," admitted 2017 junior champion Davidovich Fokina, who needed five match points to seal the win.
Two-time winner Andy Murray also made it through, coming from a set down to see off Australia's James Duckworth, who hasn't registered a single win in 2022.
Murray won 4-6, 6-3, 6-2, 6-4.
"I'm getting on a bit now so don't know how many more chances I'll get to play on Centre Court," said the 35-year-old.
Around two hours of play was lost on Monday due to rain -- and 10 matches cancelled -- but that did not faze new women's world number two Ons Jabeur.
The Tunisian, a quarter-finalist in 2021, eased past Swedish qualifier Mirjam Bjorklund 6-1, 6-3 in just 54 minutes under the Court One roof.
World number three Anett Kontaveit began her bid to reach the second week for the first time with a 7-5, 6-1 win against Bernarda Pera of the United States.
US Open champion Emma Raducanu beat Alison van Uytvanck 6-4, 6-4, much to the delight of a partisan home crowd on Centre Court.
The 10th seed became the first British female player to win a Grand Slam singles crown since Virginia Wade at Wimbledon in 1977 when she triumphed in New York last year.
"It's an incredibly special feeling to be back at Wimbledon," said the British number one, who reached the fourth round last year.
Australian Open finalist Danielle Collins was the day's biggest casualty as the seventh-seeded American was knocked out by Marie Bouzkova of the Czech Republic.
The world number 66 clawed back from a break down in the final set to win 5-7, 6-4, 6-4.
Casper Ruud won a match at Wimbledon for the first time with a straight-sets victory over Albert Ramos-Vinolas.
Third seed Ruud, who was runner-up to Rafael Nadal at the French Open, came through 7-6 (7/1), 7-6 (11/9), 6-2.
John Isner fired 54 aces and 97 winners to knock out French qualifier Enzo Couacaud 6-7 (6/8), 7-6 (7/3), 4-6, 6-3, 7-5 and will next face Murray.
Covid for Cilic
However, Marin Cilic, the 2017 runner-up, withdrew before hitting a ball after testing positive for Covid-19.
Beatriz Haddad Maia, who arrived with a season-leading 12 match wins on grass with title runs at Nottingham and Birmingham, fell at the first hurdle.
The 28th-ranked Brazilian lost 6-4, 4-6, 6-2 to Slovenia's Kaja Juvan.
After a cancelled edition due to the pandemic in 2020 and a reduced-capacity tournament last year, Wimbledon has returned to full crowds for 2022.
However, missing from the line-up are a host of Russian and Belarusian players who were banned following the invasion of Ukraine, including men's world number one Daniil Medvedev.
Eight-time champion Federer is also absent as he recovers from knee surgery.
However, Serena Williams will play her first singles match since last year's championship as she bids again to equal Margaret Court's record of 24 Grand Slams.
The American star, a seven-time champion at Wimbledon, gets her campaign under way on Tuesday as does Rafael Nadal.
The Spaniard has already collected the Australian Open and French Open this year to put himself halfway to a first men's calendar Grand Slam since 1969.