Djokovic thanks 'miracle pills' after Wimbledon win
The veteran Serb, a seven-time winner at the All England Club, beat French world number 41 Alexandre Muller 6-1, 6-7 (7/9), 6-2, 6-2 in a late-night match on Centre Court.
Djokovic dominated the first set, breaking three times, but Muller levelled the match after taking the second set tie-break.
The sixth seed resumed normal service in the third set and a couple of breaks in the fourth set sealed the deal.
"I enjoyed myself, obviously a bit less in the second set but I went from feeling my absolute best for a set and a half to my absolute worst for about 45 minutes," he said.
"Whether it was a stomach bug, I don't know what it is.
"I struggled with that but the energy came back after some doctors' miracle pills and I managed to finish the match on a good note."
Djokovic said he was delighted to be back at Wimbledon.
"I have to acknowledge the sacredness of this court, of this tournament," he said.
"It has always meant a lot to me and many other players. It's a childhood dream tournament, so I never take anything out on the court for granted."
Djokovic has been tied with long-retired Margaret Court on 24 Grand Slam singles titles since 2023 and he believes his most realistic hope of a historic 25th win lies at the All England Club.
The 38-year-old, who has lost the past two Wimbledon finals to Carlos Alcaraz, has the added incentive of pulling level with the retired Roger Federer, who won a record eight men's titles at the All England Club.
Djokovic has been in every Wimbledon final since 2018 but knows time is running out as Alcaraz and Jannik Sinner establish a stranglehold at the top of the men's game.