Eight-time champion Roger Federer survived a first-set scare to see off South African debutant Lloyd Harris and reach the Wimbledon second round.
Federer, 37, moved through the gears to win 3-6 6-1 6-2 6-2 on Centre Court.
After Harris left the crowd stunned by taking the opener, Federer began to find his rhythm and rattled off victory in one hour and 50 minutes.
The Swiss, aiming for a record-extending ninth men's title, could face Britain's Jay Clarke next.
Clarke, 20, is out on court against American Noah Rubin, with a prize of meeting the 20-time Grand Slam champion awaiting.