Laura Trott won the Track Cycling World Championships omnium to take Great Britain's fifth gold medal of the final event before the London Olympics.
Trott held a two-point lead over Australia's Annette Edmondson entering the last of the event's six disciplines, the 500 metres time-trial, at the Hisense Arena in Melbourne.
The Briton and Edmondson were head to head on the track in the final heat of the two-lap race and Trott finished first in 35.173 seconds to earn overall victory by three points.
It was the first individual world title for the 19-year-old from Cheshunt, Hertfordshire, who is now a three-time world champion, after being part of the British squad which successfully defended their three-kilometre team pursuit title on Thursday.
It was a performance which suggested Trott, who will be 20 on April 24, can win Olympic gold in the event in August.
"I couldn't ask for much more coming into London," she said.
"I didn't expect to win. I thought maybe I would pick up a medal, because I had been in the World Cups, but to win - what more can I ask for?"
Trott finished second in the flying lap, eighth in the points race and won the elimination race on Friday, before placing third in the 3km individual pursuit and 13th in the scratch race on Saturday, marking Edmondson throughout.
And the 500m time-trial triumph sealed a sensational overall victory.