Walker qualified fourth out of her best-of-three semifinal, but a blazing start and a gutsy decision on her first corner set her up for a medal.
Only Mariana Pajon, the super-quick Colombian who got through her four races unbeaten, was better, winning gold in 37.706s. Walker was .427s behind - about a bike length - while her training partner, the Netherlands' Laura Smulders, was third.
"There's a little bit of disbelief, I guess," Walker said. "It's been a long of hard work to get to this point, especially after dislocating my shoulder three months ago."
Walker had genuine fears that would be her Olympics finished. She didn't want to come to London just to say she was a two-time Olympian. She only had eyes for the podium.
"Any crash between then and today could have put me out. But if I didn't push myself and push that limit and challenge myself I wouldn't be on the podium today.
"Every day was scary for me while I was training. Once I got here it was the easy part because I was here."
Watching Walker, 24, in the crowd were her parents Sue and Graham, and younger brother Matt. It was watching Matt haring around a BMX track in Kawerau that drew Sarah to the sport.
The Walkers were in Beijing en masse, too, but only after they had become victims of an internet scam. Having missed out on tickets from the New Zealand Olympic Committee's official agent, Premier Events Asia Pacific, they turned to beijingticketing.com, a bogus Arizona-based website.
The Walkers eventually received tickets through Premier Events, but were left out of pocket until the good folk of Kawerau chipped in and raised $5000.
Walker finished fourth in Beijing, so all in all, the Walker family experience was much more satisfying this time around.
"I got an amazing start in that final and I'm ready proud of today," Walker said.
"Going into the Olympics I thought I could win it but when I woke up I had a lot of doubts in my mind and I kind of fought through those and got to the gate really focused and not afraid of crashing.
"I was ready to go down in a pile on the first corner if that's what it needed. I didn't want to get to the finish line having backed off just to avoid a crash that might have happened."
The story did not have a happy ending for Marc Willers. In sensational form in yesterday's quarter-finals, he misjudged a series of bumps and crashed heavily in his first semifinal.
He returned for the second race but was too banged up and drifted across the line a distant last.
"It's just gutting. I wanted it to go differently.
"I made a costly mistake and smashed my legs on something. I tried to start the [second] race but there was nothing in there."
Willers opted out of his third semifinal, his Olympics cruelly ended.
- Dylan Cleaver, NZ Herald
