The 25-year-old from Victoria captured Canada's first medal of the Commonwealth Games on Thursday, a silver in the women's triathlon.
"Totally pain free. It feels so good," Sweetland said with a tired smile. "It feels unbelievable to get a medal."
Sweetland raced England's Jodie Stimpson neck-and-neck through the 10-kilometre run before Stimpson pulled away down the stretch to win gold in one hour 58 minutes 56 seconds. Sweetland took the silver in 1:59.01, while England's Vicky Holland crossed in 1:59.11 for bronze.
Calgary's Ellen Pennock crashed on her bike and has a broken collarbone. Sarah-Anne Brault of Winnipeg was instructed to drop out during the run to focus on Saturday's relay race.
Andrew Yorke of Caledon, Ont., finished fourth in the men's race.
Sweetland's race to the podium closed the book — finally — on a dizzying bad-luck story that began when she missed out on qualifying for the 2008 Beijing Olympics and included suffering seven stress fractures and a torn plantar fascia.
"We're talking about a redeveloping Kirsten here, so awesome. Awesome for Kirsten," said Canadian coach Jaime Turner. "She ran really tough today, I thought she was quite clinical and ruthless out there.
"Let the players play and she followed and came up with an awesome result."
Sweetland was a rising star in the triathlon world when she became the youngest Canadian to win a World Cup race at the age of 18. She was on pace for a spot on the Beijing Olympic team, standing third in a qualifying race in which she needed only to finish top-eight. But she fainted 400 metres from the finish line.
From that point on, it's been years of one stress fracture after another, first in her tibia and then her pelvis — she'd later discover the trouble stemmed from one of her legs being longer than the other. The most severe injury was the torn plantar fascia — the connective tissue that runs along the bottom of the foot.
"I would get the whole winter of training done, nobody knew that I was working hard, and then right about race season I'd be out again. And again. And again," she said.
Last season was the first in years that she managed to put some races together, only to suffer a stomach ailment last summer that was diagnosed as a severe allergy to eggs and milk.
"So this is the first year that I'm making it through a whole season," she said.
Still, her confidence had seeped away with the long months and years of being out and wasn't restored until 10 days before Glasgow, when she raced to bronze in a World Triathlon Series event in Hamburg, Germany.
"That's huge," she said of the mental component of racing. "Until that race I wouldn't have believed I could get a medal today.
"I still put these girls on a pedestal. You start to lose a bit of confidence in your running because running is something you need to consistently do. Doesn't matter how talented you are and how much speed you have, to have to consistently train in order to be up with the best. And it had been so long since I had that so I started to lose that (confidence)."
She wasn't lacking for any Thursday. The five-foot-four Canadian was 11th in the 1,500-metre swim but laid down the fastest time in the 40-kilometre bike to put her second going into the 10-kilometre run. And then it was a foot race between the top six athletes, with Sweetland and Stimpson barely giving an inch to the other until the home stretch.
"I just tried to stick on Jodie's shoulder for the run and hang on for as long as I could," she said.
Sweetland was asked if she feels sympathy for Canadian teammate Paula Findlay, who finished last at the 2012 London Olympics amid a series of soul-crushing injuries and ailments of her own. Findlay wasn't on the team for Glasgow.
Sweetland nodded yes, she understands. The two, in fact, have been each other's cheerleader in their attempts to return to top health.
"It's really just your approach to it and how your roll with it," Sweetland said. "It's about putting in the work and not expecting the results.
"When athletes are younger and don't have injuries to deal with, they think of the work as a means to an end. But if you enjoy the work and put it in without expectations, it just sort of comes up. It feels like I didn't even work for this, it's been so fun."
The 25-year-old Yorke was 17th out of the water, then 13th after the bike, but made up ground in the run portion. English brothers Alistair and Jonathan Brownlee already had more than a minute's lead on the field by that point, Alistair going on to win gold and Jonathan taking silver.
Richard Murray of South Africa won the bronze. Yorke outsprinted Australia's Ryan Bailie to nab fourth by three seconds.
"I thought that if everything went absolutely perfectly, and some people kind of tanked, I could have come third, but it's always a dream," Yorke said.
"But to find myself running in fourth, I told myself this morning I had nothing to lose, and that was my motto the whole day. I was out there thinking 'You're hurting, but just kick. What's the worth thing that's going to happen?'"
The Canadian crossed the finish line then wobbled on his feet for a few steps before dropping to the ground. An official leaned over him to dump water on his face.
"I think that was just more indicative of my effort with the kick (than the heat)," he said.
A huge crowd turned out for the first medal event of the Games, packing the grandstand at the finish line. They stood a dozen deep at some spots along the picturesque course at Strathclyde Country Park on the southeastern edge of Glasgow, enjoying the cloudless sky and temperatures that soared to 26 C.
Sweetland's medal and Yorke's fourth-place finish were the bright spots on an up and down day for Canada. Pennock and Sweetland had come out of the water virtually even before Pennock crashed twice in the bike portion.
The first came when she appeared to clip the back wheel of South Africa's Kate Roberts, sending the two crashing to the road. The second incident saw her go down when she clipped her wheel on a barrier. She was taken from the course by ambulance to the Games' medical centre.
"Oh no, Ellen's my good friend and my little buddy," Sweetland said, when informed of the crash. "That's terrible to hear."
Turner made the decision then to pull Brault from the race early on in her run.
"We need Sarah-Anne in two days time with fresh legs," Turner said. "There's no point Sarah marching on in the individual race without being in a dominant position."
Brault, 24, struggled on the swimming portion, coming out of the water in 16th place.
"Today wasn't there," Brault said. "It's really disappointing because I thought I was ready to have a good one, and I think it would have been a lot fun to race up at the front with the girls but when you come out of the swim that far back (it's difficult to make up much ground)."
Kyle Jones of Oakville, Ont., was 11th in the men's race, while Matthew Sharpe of Campbell River, B.C., was 21st.