Bernard Tomic insisted he was not distracted by the presence of his controversial father as the Australian suffered a first-round exit at the Aegon Championships at Queen's Club, losing 6-4, 7-6 (7-4), 7-6 (7-4) against Germany's Benjamin Becker.
Tennis authorities gave John Tomic a worldwide ban from watching his son's matches in person after he was charged by Spanish police for allegedly assaulting his son's French hitting partner, Thomas Drouet, during the Madrid Masters earlier this year.
Drouet suffered a broken nose and back injuries after being allegedly headbutted and Tomic senior is due in a Madrid court in October in relation to the assault allegations.
Tomic senior was told to stay away from the recent French Open and security guards were issued instructions to bar him from entering.
Queen's chiefs upheld the ATP ban but agreed to let him pay for a spectator ticket for his son's first-round match , provided that he agreed to behave himself.
There were no controversial antics from Tomic senior but his son, struggling with a leg injury, was unable to end his poor recent run.
Tomic's world ranking has dropped to 63rd after a dismal run, which has seen him win just two of his past eight matches.
He hadn't been beyond the second round of any tournament since reaching the quarter-finals in Marseille in February and this was a dispiriting preparation for Wimbledon, which begins in less than two weeks.
Yet he said: "I didn't see my father, to be honest. Funny you spotted him and I didn't. That's interesting.
"I expected him to be here. I knew he was at my hotel. I saw him in the morning. I had breakfast with him.
"It wasn't really something I was focusing on. I knew it was going to be a tough match.
"Becker had more matches than me on grass. He had been playing really well, made the final of the challenger last week. He was a dangerous player.
"It was a tough tie-break in the end but I'm happy the way I played. I think it was a good match for my first match on grass and especially back from my injury."