The fastest man on earth smashed his own record defending his 100m title and then delighted the crowd with his trademark “Lightning Bolt” pose.

But today we can tell for the first time how he was spurred on to the finish line by an image of sexy Megan Edwards’ perfectly-formed bottom.

Junior athlete Megan had sent Bolt a photo of her cute rear before the race, along with the message: “Think of my bum at the finish line lol.” Jamaican superstar Bolt, 26, replied before the August 5 event at London’s Olympic Stadium: “I can do that.”

After 80,000 spectators and millions watching on TV saw him run a blistering 9.63 seconds to claim his first gold medal of the Games, Megan texted to congratulate him.

And he wrote back: “I was thinking of ur ass.”