Alcaraz, who reclaimed the world number one singles ranking with his US Open triumph this month, partnered with Jakub Mensik and guided Team Europe to a 7-6(7), 6-4 win over Taylor Fritz and Alex Michelsen in the final match of the day.
"I think that it gives you more opportunities to make great shots, great volleys," Alcaraz said about playing doubles.
"But doubles is not just about one player. It was a team (effort) with a great player in Jakub. He has great skills in points throughout and made me comfortable on the court."
Competing in his first tournament since capturing his sixth Grand Slam title, Alcaraz produced moments of magic from the net and the baseline while Mensik brought the power as they grabbed a decisive break in the 10th game of the second set to prevail.
The three-day Laver Cup, viewed as tennis' answer to golf's Ryder Cup, offers fans a rare opportunity to see the sport's top players team up, with the first side to reach 13 points from a total of 24 available declared champions.
As in previous editions, match victories on the opening day are worth a point each, with two points awarded for wins on the second day and the stakes get higher with three points each on the final day of action on Sunday.
Norwegian Casper Ruud landed the first punch for Team Europe at the Chase Centre with a 6-4, 7-6(4) win over Team World's Reilly Opelka, before Mensik earned the next point for the holders by beating Michelsen 6-1, 7-6(3), 10-8.
Brazilian teenager Joao Fonseca pulled a point back for Team World as he fought from a break down to claim a 6-4, 6-3 win over Flavio Cobolli and ensured that five-time champions Team Europe would not complete a clean sweep.
"I knew it was going to be a difficult match and I knew how important it was," Fonseca said.
"I'm happy with the way I managed to stay positive during the match. I like to play aggressive, so I wanted to suffocate him ... not let him breathe and not give him space."