Tom Daley survived a major scare as he left it until his final dive to nervously progress past the first round of the men's 10-metre platform on Friday night.
The 18-year-old former world champion produced one of the worst displays of his decorated young career before narrowly sneaking through to Saturday morning's 18-man semi-final.
Veteran team-mate Pete Waterfield was not so lucky, as he too under-performed in his fourth Olympics, to bow out in 23rd.
Daley was left on the cusp of a shock exit when drew scores as low as three for a disastrous penultimate back three-and-a-half somersault - the dive that cost him and Waterfield a medal in the synchro last week.
With the 17,500 home fans inside the Aquatics Centre left stunned he held his nerve to grab 8.5s for his final reverse three-and-a-half somersaults and edge through.
China's Qiu Bo, who snatched away Daley's world title 12 months ago, immediately stamped his authority on the competition qualifying in first place with 563.70 points.
Daley had arrived at these Olympics in career-best form after producing a personal best 565.05 in his last international competition before the Olympics in May.
That had raised expectation that Daley, one of the British poster boys for these Olympics, could test Qiu for gold.
Instead he was left scrambling just to make it into Saturday's action as he lurked just two places above the cut-off heading into the final round.
Daley's nerves were immediately evident when he uncharacteristically over-rotated on his opening back two-and-a-half somersaults with two-and-a-half twists to leave him right on the cut-off mark.
He then appeared to respond to the danger with scores of 8.5 for his next inward three-and-a-half somersault - his easiest dive - before nailing a handstand.
That elevated Daley safely back into the top-10 at half-way but when he bombed his penultimate leap he dropped dangerously to 16th.
That left a now nervous home crowd holding their breath as he leapt for his final dive, before they roared as one as scores of 8.5 saw him through, albeit in 15th.
Waterfield, who was raised in nearby Walthamstow, saw his hopes of progressing jeopardised by a horror opening that left him second last after two rounds.
After missing his armstand Waterfield's second inward three-and-a-half somersault threw water everywhere on entry to attract fours.
The veteran proved his fighting qualities with nines for his hardest forward four-and-a-half somersaults before winning eights for a back three-and-a-half somersault - the dive that left him apologising to Daley last week.
But just as he got in touch with the top-18 he missed his penultimate dive to crash out of contention.
"That was far too close for my liking," Daley said.
"It was a tough competition out there. I don't normally compete at that time of night for one and there was the 32 competitors in it as well meaning you had to wait half-an-hour between dives.
"Towards the end of my list my legs were starting to fail on me. I was getting tired. It was one of those things where you wanted it to be over but also be comfortable in making the semi-final.
"I've done my job today but not by the most comfortable of margins. But I'm through to tomorrow and tomorrow's another day."
Daley claimed that tiredness was the reason behind his flopped fifth dive and thanked the home crowd for giving him the energy to recover from the mishap.
"With the fifth dive, like I said, my legs were starting to get a bit shaky," he said.
"I was just generally starting to get a bit tired. I was trying to keep up my energy but definitely the home crowd on that last dive got my adrenaline pumping again."
Asked about how he felt before his final dive, he said: "It was one of those feelings where I was stood up on the end of the board and I thought 'you know what, I can only do what I can do'.
"So I went out there and gave it my best shot and made sure I was jumping the right height, spinning the right speed and kicking out at the right time.
"The home crowd really did give me that extra adrenaline boost to give me the energy to get my dive on my head."
Waterfield was third at the World Cup at the Aquatics Centre in February but revealed nerves had got the better of him on Friday.
"There was a lot of pressure with a home crowd," he said.
"Normally it makes me dive better. I didn't feel nervous until I literally stood on the board.
"That was weird. I felt good and then the nerves came on the board - you don't get time to get used to them then.
"Unfortunately I had a bit of a bad day."
The veteran has endured an injury-interrupted six months and hinted he would now concentrate on the platform synchro only.
"I'm going to keep going on but my body is screaming out at me a little bit," he said.
"I might just stick to doing the synchro and leave the individual. We'll see.
"I've got some decisions to make."
He also backed Daley to recover and challenge for the medals.
"It's a new day tomorrow that's the thing with the prelims," he said.
"Just getting through it. You just have to land on your head and you get through, but I didn't.
"If I had of done tomorrow's a new day. You can relax and forget about it.
"I'm sure Tom won't disappoint."