Rebecca Adlington is pride of pool after battling for bronze

It was not the gold medal of Beijing but it was still a performance to be proud of for Rebecca Adlington. Condemned to swim in the same outside lane from which Michael Phelps had failed so dispiritingly on the opening night, Adlington exchanged sixth at the halfway point for a bronze medal by the finish, Britain's second of its own Games. After the premature nerves roused by the blank of day one, Britain are on the board at London 2012.

On a night full of sound and fury as the London Aquatics Centre came boisterously alive, the result signalled everything. The 400m freestyle is not Adlington's main event and after a misjudged swim in the heats directed her to lane eight – away from where the medals are usually settled – getting anywhere near the podium was a strenuous demand to make.

"After only qualifying eighth I didn't know what to expect, and there was no pressure on me at all," said Adlington. "I know everyone else wanted to say: 'Oh you got the gold in Beijing'. But to me I was not expecting that at all, so I am so, so pleased with [bronze]."

She was emotional afterwards too, the tears welling up. She confessed to juggling a bundle of nerves before her race as she found the support of the majority of the 17,500-crowd almost overwhelming.

Like Hannah Miley on the previous evening, Adlington failed to match the time she recorded at the trials in the same arena in March. Then, though, there were only a few thousand in attendance.

"I'm crying because the crowd is so overwhelming," said Adlington, speaking poolside. "Twelve years of hard work has gone into that and it's hard, it was so hard. It's always the 400m that feels tougher than the 800m. I'm so glad I got a medal at a home Games, not many people can say that.

"We're not used to this – it is all new to us. I felt really emotional before my race and those emotions are going to take their toll on you."

She never threatened to take gold – that went to France's relentless Camille Muffat, who led from start to finish, and her sidekick Allison Schmitt, the in-form American. But this was a good swim and one that her coach, Bill Furniss, the man who steered her to her triumphs of Beijing and helped repair her post-Olympics crash, will be happy to settle for.

When the 23-year-old finally clambered out of the pool it was to Furniss she turned, climbing into the spectator area to hug him. Furniss had the perfect view of her race, being in the front rows as she ploughed down the adjacent lane eight. From lane one to eight it was a formidable field; six of them had a strong claim on a medal.

"Not expecting anything," Adlington had tweeted as she rested in the village yesterday afternoon. Expectation has accompanied her every step of the way in the build-up to London. It has been a tough Olympic cycle for Adlington, who came out of the pool in Beijing and into a new life.

When she got back in the water she struggled to adapt to her new status; the hunted rather than the hunter. The first two years post-Beijing were notable for disappointing results – there were very different tears after failing to win a medal in the 800m at the European championships.

But with the help of Furniss's firm guidance and the assistance of Simon Middlemas, the swimming team's psychologist, she picked herself up again.

She has trained well this year, missing only two days, back to 20 solid hours in the pools, 70km a week up and down her home pool in Nottingham and added gymnastics to her schedule to improve her turns.

But it was her familiar staying power that was vital last night. Furniss instructed her to pace herself to begin with – in the morning she had torn off the blocks and then slowed. At the halfway point she was sixth, but then, as the distance lengthened, she began to make headway: a length later fifth, one more and it was fourth and at the final turn, when the scoreboard showed her third.

The loudest cheer of the night in an arena that was at last raucous (and all but full) accompanied her down the final length, closing on the leaders and ensuring a deserved bronze reward.

Still no Briton has ever defended an Olympic title in the pool. That remains the burden that will accompany Adlington for at least another four days but at least she will do so with the happy consolation of a medal, and the knowledge that the 800m is her event.

The evening's racing had begun in spectacular fashion with Dana Vollmer of the US setting the second world record of the Games in the 100m butterfly. It is a second Olympic gold, but first in an individual event, for Vollmer – eight years after she won relay gold as a 16-year-old in Athens.

Vollmer has already been swimming at the highest level for 12 years, or half her life. She was 12 when she took part in the US trials for the Sydney Games. The New Yorker had looked in ominous form throughout the early rounds and destroyed the field over the second 50m, after turning in third place, to touch in 55.98sec.

Lu Ying won silver as China maintained their impressive start to the week, while Britain's Ellen Gandy finished last in her first Olympic final, but her main event is the 200m fly – she will be back in the pool for the heats tomorrow morning.

Robbie Renwick will be back tonight to compete in the final of the 200m freestyle. It was an impressive swim by the Glaswegian in yet another high-class field.

There will be two further Britons in tonight's finals. Liam Tancock finished third quickest in the 100m backstroke and will harbour genuine hopes for a medal. "I'm proper buzzing," he said afterwards.

Gemma Spofforth, meanwhile, was sixth quickest into the women's 100m backstroke final.

The breathtaking standard of competition continued with a second world record of the night in the men's 100m breaststroke for Cameron van der Burgh of South Africa.