David Weir produced a performance of supreme confidence to qualify in style for the final of the T54 5,000 metres at the Olympic Stadium.
Weir, who won Great Britain's only athletics golds with a double four years ago in Beijing, controlled the race before hitting the accelerator on the final lap.
He could afford to slow down on the home straight and rolled nonchalantly across the line in 11 minutes 28.88 seconds.
He said: "It's a really great feeling. I did have nerves, but they were good nerves. I didn't panic at all.
"I'm in the right frame of mind and I'm in good shape. It was everything I expected so I loved it out there."
Eighteen-year-old Rhys Jones finished eighth in the 200m T37 final in 24.68, while Sophia Warner, 20 years his senior, was fourth in the T35 200m in 35.25.
Sixteen-year-old Jordan Howe made it into the final of the T35 100m as a fastest loser after finishing fourth in his heat in 13.75. But Sam Ruddock was unable to progress, coming home fifth in the other heat in 13.92.