Reigning Singapore Sportsman of the Year Joseph Schooling made a disappointing Olympic debut in his pet 200m butterfly event yesterday.
The 16-year-old, who was the first Singaporean to qualify for the Games by meeting the "A" qualifying mark, came in last in his heats, clocking 1min 59.18sec.
That placed him 26th among the contestants for the event, and ruled him out of the top-16 semi-finals.
The timing was also a far cry from his national record of 1:56.67 set in last year's South-east Asia Games - the same timing which allowed him to qualify for the Olympics.
Several lanes beside him, one of his swim heroes had a far less frustrating swim in qualifying for the 200m butterfly semi-finals.
Michael Phelps, unflustered by his slow start to the London Olympics, cruised through the heats of his favourite event to edge closer to two more milestones.
The American swam well within himself, conserving his energy for his best races which are still to come, to qualify fifth fastest overall.
Austria's Dinko Jukic was the fastest overall, stopping the clock at 1:54.79, just ahead of America's Tyler Clary, but all the top swimmers did just enough to safely get through to the next round.
"I'm pretty happy with that swim," Phelps said. "That's all I needed it to be."
He had won the event at Athens in 2004 and again in Beijing four years later. If he wins again today, he would become the first male swimmer to win gold in the same individual event at three successive Olympics.
He will also equal Soviet gymnast Larisa Latynina's record tally of 18 Olympic medals and could claim the outright record the same night in the 4x200m freestyle-relay event.
Chinese sensation Ye Shiwen set herself up for a golden double, when she posted the fastest qualifying time in the women's 200m individual medley, after winning the 400m IM in world-record time last Saturday.