Twelve years later, he swapped his seat high up in the stands for a place on the court where he gave the eight-time champion a huge scare before losing their first round clash, 3-6, 6-1, 6-2, 6-2 on Tuesday.
"I was 10 and it was the first time I had seen a pro tennis match," recalled Harris.
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"My parents snuck us on to Centre Court and I saw Federer play Marat Safin. I thought it was amazing seeing these guys moving and the way they played. Here I am, playing him a few years later."
Two-time major winner Safin was always a crowd favourite but for Harris, seeing the Swiss star win that fourth round match in 2005 was key to his decision to become a tennis player.
"Federer was always my idol. He was beautiful with finesse and the best role model for players," said the world number 86 who was making his Wimbledon debut.
Despite losing and with his chances compromised by a left calf injury, Harris will remember his Centre Court debut for years to come.
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"I had goosebumps when I walked on," he said.
"The crowd was cheering loudly and I had to take a few seconds to absorb it."
Harris said the reaction to him playing the eight-time Wimbledon champion and 20-time major winner had been overwhelming — both before and after the match.
"It was chaos. I have never got so many messages. I got thousands of messages from people I know and from people I don't know."
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