Jakarta - Singapore's Olympic swim champion Joseph Schooling shrugged off a horror turnaround on Thursday to top the heats for the 50 metres butterfly at the Asian Games after a fitful night's sleep.
The 23-year-old, who stunned Michael Phelps in the 100m butterfly in Rio two years ago to win Singapore's first-ever Olympic title in any sport, got less than five hours of shut-eye after retaining his Asian title in Jakarta on Wednesday evening.
After becoming the first swimmer to deny China or Japan a gold medal at the six-day meet, Schooling admitted to staying up late - and to drinking a few too many coffees.
"It was rough," he winced, after clocking 23.84 seconds to edge out China's Wang Peng for top spot.
"I went to bed at 01:00 and woke up at 05:57 - that's a shitty turnaround but that's what you've got to do sometimes.
"I took a lot of caffeine last night. I had about four cups of coffee, so it was hard to go to bed.
"But it's normal to feel tired. It just means you've got to grind through it. You've got to be a man, step it up and not complain."
Jordan's Khader Baqlah turned heads by posting the joint-quickest time in qualifying for the men's 100m freestyle, swimming's blue riband event.
The 19-year-old, who finished just outside the medals in fourth in the 200m freestyle final earlier this week, clocked 49.30 with China's Yu Hexin - winner of the 50m free in Jakarta.
Japan's Shinri Shioura, silver medallist at the 2014 Asian Games in Incheon, was just two-hundredths slower.
"I was kind of frustrated with the 200m," admitted Baqlah.
"That was my fastest morning swim ever today but I'm probably going to have to go mid-48 to win."
The usual suspects were lurking in the men's 200m backstroke with China's Xu Jiayu second quickest as he looks to complete an Asian Games treble in the discipline.
Xu, who could potentially finish with five gold medals in Jakarta, touched in 2:00.53 behind countryman Li Guangyuan 1:59.87.
Japan's Satomi Suzuki topped the heats of the women's 50m breaststroke as she looks to retain her title and complete a 50-100m double.
Japan's golden girl Rikako Ikee could equal countrywoman Yoshimi Nishigawa's five swim titles at a single Asian Games when she goes in the 4x100m medley relay later on Thursday.
The 18-year-old, who has emerged as Japan's brightest swimming hope for the 2020 Tokyo Olympics in her home city, has already won gold in the 50 fly, 100 fly, 100 free and the 4x100m freestyle, plus two silvers.
A medal of any colour will also see Ikee match countryman Kosuke Hagino's haul of seven, including four gold, at a breakout 2014 Asian Games.
Nishigawa won five gold medals in freestyle and individual medley at the 1970 and 1974 Asian Games.