There were tears, there were smiles and there was a noisy crescendo that the signature curved roof of the Aquatics Centre struggled to contain. This was Britain's night of nights in the pool, one that had been willed for in vain throughout the Olympics and one that arrived last night via a 17-year-old with a sense of occasion.
This was a big occasion, the biggest of Ellie Simmonds' young life, and she rose to it, winning gold by holding her nerve down the last 50m stretch, the eighth length of a 400m freestyle in which she had raced stroke for stroke against the American Victoria Arlen.
The teenaged Briton kept her nerve in exemplary fashion, coolly breathing on her left side down that final length in order to keep a watchful eye on Arlen, and in the final few metres it was Simmonds who edged clear to win by just over 1sec. That Simmonds is a winner had become apparent four years ago in Beijing, when she collected two gold medals at the of age 13, but what she achieved last night was beyond that.
Outside the pool, a 50ft image of Simmonds beams down from the shopping centre over the Olympic Park: she is the face of the British Paralympic team. Since Beijing she has become used to being stopped in the street, and with that recognition and fame has come something else, something that her Olympic counterparts in the vaunted swimming team struggled to handle.
"I have felt extra pressure," she said last night. "I felt like I had a lot of pressure on me leading into the Games because people expected me to get the gold and that wasn't going to be the case with Victoria around.
"It's all about 'take the stage' [a pre-Games slogan] and it made me want to take the stage, do it for my country and all the people who have supported me."
Before the race she and Arlen, who had been thrown out and then reinstated in the classification before yesterday, chatted in the call room beneath the stands. Outside, expectation surged around the steep stands, easily audible to the two 17‑year-olds. "We agreed 'Let's give them a good show'," said Arlen.
How Simmonds has gone about living up to what she achieved in Beijing is a template any athlete should want to follow. In the trials in February she broke the first world record, able-bodied or Paralympic, in the brand new pool. Yesterday morning in the trials she set a new personal best and last night the world record went again – it is now restored to her possession after Arlen's intrusion at the US trials in June.
All told, it is the perfect trajectory of improving with every visit to her place of work, and what is more she has relished it.
She walked out last night with one headphone in place but left the other dangling because she wanted to hear the crowd, soak up the support.
"It definitely is a home advantage, gives you an extra buzz and makes you want to do the best you can," she said. "I knew I would have to give it all I've got and that last 50 hurt. It just killed me. I was so pleased to touch.
"My race plan was to stay with her for 200 and then kick my legs for the last 200 and go for it. She was with me all the way and that last 50 I saw her and gave it everything. When I touched I had no energy left. I had to dig deep and dig up everything."
There were two other British medals in the pool last night. Claire Cashmore collected a silver in the SB8 100m breaststroke and Matthew Whorwood a bronze in the S6 400m freestyle.
What to watch
Dogfight at Dorney
Great Britain's rower Tom Aggar, who has never tasted defeat since making his international debut in 2007, goes for gold in the singles sculls final at Eton Dorney. China's Cheng Huang, poses a threat after breaking Aggar's world record time in his heat to qualify. "It will be a real dogfight in the final," Aggar has warned.
Timing From 9.50am
Out of the Woods
Shelly Woods originally won silver in the T54 5,000m in Beijing, but then the race was restaged four days later after a crash involving six riders, and she finished a place worse in third to take home bronze. The Blackpool wheelchair racer will be going straight for gold this time round.
Timing From 10.37am
Return of the old enemy
Old rivalries will resume as Great Britain take on Argentina in five-a-side football in a preliminary round Pool A fixture at the temporary Riverbank Arena.
Timing 3.30pm kick-off
Does Bayley have the X Factor?
The former table tennis world no 1 in the class seven category, Will Bayley, could challenge for gold at the ExCeL. The 24-year-old is no stranger to performing under the lights - he went to the famed BRIT school, whose alumni includes pop stars Adele and Jessie J.
Timing From 5.15pm
Not a slow Ballard
Graeme Ballard, who set a new world record at the World Cup in May, is one of the favourites in the T36 100m finals. Fellow Brit, Ben Rushgrove is also in contention, and will hope to improve on his silver in the event in Beijing in 2008.
Timing From 7.48pm
Blind sprinter Libby Clegg races in the T12 100m finals. Her current running guide, Mikail Huggins, is the stepson of her former guide, Lincoln Asquith, with whom she won silver in the event in Beijing. But unlike Asquith, Huggins will be rewarded with a medal this time round if they seal a podium finish. It could the start of a glorious week for the Clegg family, her brother James will be in action in the S12 50m freestyle swim on Friday.
Timing From 7.54pm
Can Pistorius deliver first blow?
The South African blade runner, Oscar Pistorius has the first chance to defend one of the three T44 events he won in Beijing in the 200m final, but will be up against his American rival, Jerome Singleton, a rivalry Pistorius has previously likened to boxing greats Muhammad Ali versus Joe Frazier. Pistorius also won the 100 and 400m in 2008.
Timing From 9.15pm
Weir rides on
The British wheelchair athlete David Weir aims to secure his seventh Paralympic medal, and third gold when he competes in the T54 5,000m. Weir's main challenge will come from Switzerland's Marcel Hug, and Australia's Kurt Fearnley, who was victorious in the event in 2004.
Timing From 9.49pm