Amy Hunt burst into tears immediately after blazing to a brilliant silver medal in the 200m final at the World Athletics Championships in Tokyo.
It was Great Britain's second podium of these championships, achieved in 22.14 seconds behind the United States' Melissa Jefferson-Wooden, already the 100m champion in Japan, who crossed the line in 21.68s.
Shericka Jackson collected bronze for Jamaica in 22.18s, while Dina Asher-Smith finished fifth.
The race required a restart after the Bahamas' Anthonique Strachan was disqualified for a false start.
A beaming Hunt told the BBC: "I have not stopped smiling or crying! As soon as I saw my mum, I burst into tears.
"I knew I could do it -- as long as I put in a good turn and was with them off the bend. I am so proud of myself. I just beat some amazing girls and I can't believe it.
"Moments before the race, I just thought of my Grandad. I knew he was watching over me, I knew he was going to guide me. I have a tatoo of his name on my arm."
Asher-Smith was fastest out of the blocks in 0.147s and in bronze medal position at the halfway point behind Jefferson-Wooden and Jackson before Hunt found another gear.
It was an emphatic statement from the 23-year-old, who before these championships admitted she had fallen into quite "a few years of huge obscurity" after deciding to complete her English degree at Cambridge and recovering from major injury and surgery.
Asher-Smith was thrilled for Hunt but a little disappointed with her race.
"Amy did incredibly, bless her," she told the BBC. "I am a bit disappointed in my race. I could have done better with executing and I have to go away and work on that."
Keely Hodgkinson, meanwhile, has admitted the unusual warm-up conditions have added an extra challenge in Tokyo.
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The Olympic 800m champion took the next step in her chase of a first world title by winning the third heat in 1:57.53 to book a place in the final alongside training partner Georgia Hunter Bell.
Yoyogi Park, where the warm-up track is located, is not -- as is common -- next to the stadium, but a drive away. Google Maps estimates it takes six minutes, but the PA news agency understands the commute is actually closer to 15 minutes.
"It doesn't feel good out there," two-time world silver medallist Hodgkinson, after emerging fourth-fastest of the semi-finalists, said.
Pressed further, she explained: "I think the whole warm-up situation, you're warming up for almost two hours. It can be quite draining, so maybe we will have to look at doing something better come Sunday.
"But other than that, I'm happy to be in [another] world final. That's an achievement in itself. I'm really happy to do that and be in the picture for another medal, hopefully."
PA has contacted World Athletics for comment.