Imagine getting within metres of the finish line of a half marathon and then turning round to see your partner on one knee.
But instead of pulling a muscle, Felix Harkness, 39, pulled a ring out to propose to his partner in front of thousands of people.
Anna Bearne, from Bristol, said she was "still in shock" and "so chuffed".
The couple finished the race in one hour and 43 minutes and have another planned in order to go quicker.
Ms Bearne, 38, and Mr Harkness "caught the running bug" just over a year ago and train together.
The Cardiff Half Marathon on Saturday was the couple's third race over the 13.1-mile (21km) distance.
"I cannot believe he did it there and then," said Ms Bearne.
She said she had "absolutely no clue" the proposal was coming.
She said they had been training for 12 weeks and had both hoped to beat their personal bests.
"We were really excited about it and then 14km (8.7 miles) into it, I think the stress of it might have got to Felix and he just started hitting the wall.
"He just ran out of energy, could barely move his legs in front of one another - which is so unlike Felix, he's usually the one pulling me along," she said.
"I was really cross half way around, I was really like 'there's just no point in finishing'... and he said 'no really lets just make it to the end, I don't give up on races'."
When they got within metres of the finishing line, Mr Harkness decided it was time.
"He pretended to pull something in his leg and went down on the floor and I turned around and was like 'come on' and then he pulled a ring out of his pocket," Ms Bearne said.
Ms Bearne said they missed their target time by seven minutes.
"We train together and we just started running just over a year ago and we realised we loved it.
"We just got the bug and we've actually booked another [half marathon] in two weeks time so we can get the pace that we want," she said.
Their three children, Fox, 6, Woody, 4 and Hero, 2 are "excited" for the "big party" the couple are now planning for their wedding, the soon-to-be bride said.
(bbc.com)
