David Nalbandian described his disqualification from the final of the Aegon Championships at Queen's as the "worst moment" of his career.
Nalbandian had taken the first set 7-6 against Marin Cilic, but lost his serve in the second set to trail 4-3 when the incident occurred.
The 2002 Wimbledon finalist kicked an advertising board that left line judge Andrew McDougall nursing a bloody gash on his leg.
"I know that I made a mistake, 100 percent, and I apologise. I feel very sorry to the guy. I didn't want to do that," Nalbandian said after the match.
"But sometimes you get angry and can't control yourself in moments like that," he added.
But the Argentinian vented further anger towards the ATP, the game's governing body, for his disqualification: "Everybody makes mistakes, right? When somebody else does a mistake, they have to pay in the same way, but they players don't feel that happens much, especially with ATP," he said.