The 22-year-old, already a runner up in the scratch race and Madison in Hong Kong, went into the week targeting the points race and after winning two team pursuit gold medals in previous championships, she put on an exhibition to take individual gold.
For much of the proceedings it was a two horse race with decorated American rider Sarah Hammer, but the Brit came out on top courtesy of an incredible burst of speed in the final lap.
And for Barker there was a sense of relief at, as she Tweeted following her earlier silver medals, no longer being the bridesmaid.
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"I'm incredibly happy, so, so happy. I've had two silvers this week and until the last lap it looked like it was going to be another silver," she admitted.
"So I was already a little bit heartbroken at that thought, but I'm so relieved that I've got a gold.
"The crowd were amazing and I've got a lot of teammates who came to see me, came to trackside.
"I could hear them all the way round, it was great."
Elinor Barker takes world silver in scratch race
Barker failed to score in the opening three sprints, but won the fourth and straight away set about taking a lap on the field, alongside five-time individual pursuit World Champion Hammer.
In doing so the Brit also won the next sprint, establishing a commanding lead over all but her American rival, meaning the pair would mark each other for the remaining 50 laps.
Hammer was the next to get away, gaining a lap and taking the lead, but Barker set off in pursuit and with laps rapidly ticking away, she took the lap herself and assumed the gold medal position.
Three laps later a burst of speed saw her finish sixth in the final sprint, six places clear of Hammer and more than enough to seal victory.
"It was really, really, hard, she's such a tough competitor and was really hard to race against," added Barker, part of the World Record setting team pursuit Olympic champion quartet from Rio 2016.
"I just somehow had some legs for the last five laps.
"I had to use my sprint a little bit earlier to catch up to her, and then it was just a case of trying to hold on."
Earlier in the day Katy Marchant missed out on the keirin final after finishing fourth in her heat and failing to make it through the repackages.
The week ended on a high for Joe Truman however, with the 20-year-old recording a personal best in qualifying for the kilometre time trial - his time of 1:01.429 placing him 11th overall.
But the final race of the week saw Mark Stewart and Ollie Wood fail to finish in a pulsating Madison race - won last year by Sir Bradley Wiggins and Mark Cavendish in London - to leave Great Britain joint fourth in the final medal table.
Track World Championships
Britain's Elinor Barker claims points race gold at World Champs