The world number three, playing in only his second event since a four-month injury lay-off, impressed the watching Rod Laver and Roger Federer as he and Mensik defeated Alexander Bublik and Taylor Fritz 6-4, 6-4.

Alcaraz plans to play fewer events going forward, blaming an "impossible" tennis calendar for a rising number of injuries in the sport.

But the seven-time Grand Slam champion said before the competition that his "love" for team events helps him "bring my joy back on the court, bring my joy back on playing tennis."

He and Mensik were all smiles as just one break of serve sufficed in each set to earn an opening day lead.

Alcaraz and Alexander Zverev, the reigning French and US Open champion, were both kept in reserve by European captain Yannick Noah earlier on Friday.

Casper Ruud earned the first point of the tournament by edging out Francisco Cerundolo 10-8 in a deciding tie-break.

Brandon Nakashima responded for Team World, also edging out Mensik in a tie-break after the first two sets were shared.

Rising Spanish star Rafael Jodar was more convincing on his Laver Cup debut with a 6-2, 6-3 win over Bublik.

The first side to 13 points will be crowned winners of the three-day event at London's O2.

Each match is worth one point on Friday, two on Saturday and three on Sunday.