The 37-year old star was surprise addition to the torch relay and performed a short moonwalk as the crowd roared.
"I moonwalked on the torch run. I was thinking 'me and Michael' ... I don't want to Tom Jones it right now," he said. "Me and Mike were really close and he would have been proud that I ran the torch, so I thought why not moonwalk it a couple of steps while running with the torch."
The star, whose real name is William Adams, says he's known for about a year that he'd carry the torch but was told not to tweet about it. Now famous in Britain as a judge for "The Voice" TV singing competition, he held his phone in the air as he got started, asking people to follow him on Twitter.
"This is top notch. I have got Grammys and stuff but this is different," he said. "I had some video cameras that were recording me running the torch, so I am going to do a video to my moonwalk moment.
"So I am thinking about doing a little Olympic mash-up."
The star shared honours with James Winter, a 40-year-old milkman from Chard, who also carried the torch. The person who nominated him said the community relies on Winter in all weather.
"Even in the deepest snow he manages to deliver extra milk and make sure the elderly people on his round are okay and have enough supplies," the nomination said.
Organizers have said they want the torch run to honour local unsung heroes.
Earlier, in the day, the Olympic torch was briefly snuffed out as it was attached to the side of Para-badminton player David Follett's wheelchair in the western England town of Great Torrington. London Olympic organizers blamed the incident on a malfunctioning burner.
Such occurrences are fairly common and organizers keep a "mother flame" in a protective lantern just in case.
Follett, who uses a wheelchair after being injured in a car accident at 19, was given a replacement torch and the relay continued.
The torch is travelling on a 70-day, 8,000-mile (12,875-kilometre) trip around the U.K., with a stopover in Ireland, ending up in London for the July 27 opening ceremony.
Some of the torchbearers who have participated so far have put their torches up for sale on eBay. One torch is reported to have been sold for more than 150,000 pounds ($240,000).
Others are listed for less. Some of the sellers said on eBay they will donate the proceeds to charity.
Unlike others, will.i.am said his torch is not for sale.
"I don't eBay," he said.