Novak Djokovic said he was "extremely glad with the way I felt and the way I played" as he won his first match since knee surgery to reach the second round at Wimbledon.
Djokovic, seeking to equal Roger Federer's men's record of eight singles titles at SW19, beat Vit Kopriva 6-1 6-2 6-2 under the roof on Centre Court.
The Serb, 37, had an operation on a torn medial meniscus on 5 June, having aggravated the problem during the French Open.
He will next play British wildcard Jacob Fearnley.
Wearing a knee support on his right leg, Djokovic showed no signs of discomfort against the 27-year-old Czech qualifier, converting his sixth break point in a lengthy fourth game before racing through the rest of the first set.
He broke again early in the second set, stretching his right leg out to stay in a rally and then, in trademark style, converting defence into attack and forcing Kopriva into going long.
Three further breaks of serve hurried him to victory, Djokovic finishing the match with three consecutive aces as he moved to the next round in style.
"I tried to really focus on the game and not think about the knee too much," the 24-time Grand Slam champion added in his on-court interview.
"Everything that I could do, I have done over the last three weeks, along with my team, to be able to play here for you today. I think if it was for any other tournament I probably would not have risked it, would not have rushed as much but I just love Wimbledon, love coming back here."
Sixth seed Rublev upset by Slam debutant
Russian Andrey Rublev became the highest seed to fall in the men's singles, losing 6-4 5-7 6-2 7-6 (7-5) to Argentine Francisco Comesana.
At one point the sixth seed smashed his racket against his own thigh six times as he was frustrated by his play, and his 23-year-old Grand Slam debutant.
American 20th seed Sebastian Korda was also beaten in the first round, losing 7-6 (7-5) 6-7 (4-7) 7-6 (8-6) 6-7 (4-7) 6-3 to French lucky loser Giovanni Mpetshi Perricard.
The 20-year-old, who is 6ft 8in tall, fired down 51 aces and saved all 11 break points he faced from Korda in his first appearance at Wimbledon.
French Open runner-up Alexander Zverev had a straightforward success, defeating Spaniard Roberto Carballes Baena 6-2 6-4 6-2.
Polish seventh seed Hubert Hurkacz saw off Moldovan Radu Albot 5-7 6-4 6-3 6-4, while Alex de Minaur beat fellow Australian James Duckworth in three tie-breaks.
American Ben Shelton, seeded 14th, was two sets to one down overnight against Italian Mattia Bellucci, but fought back when they resumed on Tuesday to win 4-6 6-3 3-6 6-3 6-4.
Danish 15th seed Holger Rune progressed with a 6-1 6-4 6-4 win over Kwon Soon-woo.