The 25-year-old blew away the field, and Daegu's "cover curse", with a brilliant display of hurdling in her 17th straight victory to take her country's first title of the championships in 12.28 seconds.
Americans Danielle Carruthers and Dawn Harper, the Olympic champion, ran personal bests but still had to settle for silver and bronze respectively sharing the same time of 12.47 seconds.
"It's been an amazing season," said Pearson. "I could not ask for more -- I just wanted this so badly.
"It feels unreal, I've been focusing on that race for about a year now, making sure I got everything right," she added in a televised interview.
"I really wanted it and I just stayed focused on every race. I knew when I got to the final I could do anything."
Having run world leading times in the heats and semi-finals, Pearson flew out of the blocks in lane three and confirmed her pre-eminence in the event this year with a third best time of the year and a world championship record.
The Olympic silver medallist, who has not been beaten this season, headed straight to a band of Australian team mates at trackside to celebrate her victory and stamp on a copy of the programme.
Pearson was the cover star on Saturday and therefore supposedly subject to the Daegu curse, which has meant the featured athlete has failed to win their event in seven out of the eight days of the championships.
Britain's Tiffany Porter clipped the penultimate hurdle and finished fourth in 12.63.
Porter, who improved her British record to 12.56 when winning her semi-final, clasped her head in her hands after she crossed the line, devastated by her mistake.
“I got a great start and I was in a very good position, I think I hit hurdle nine, everything just happened so fast, it’s kind of a blur right now,” she admitted.
“I just came out of my race and hit the hurdle. By that time it was over. I guess should of, could of, would of but unfortunately I didn't get the silver.
“I'm going to watch it probably a million times and take the positives away from that and grow into a better athlete and come back stronger for next year.”
The United States maintained their grip on the women's 4x400 metres crown with their third consecutive world championships victory.
The US quartet of Sanya Richards-Ross, Allyson Felix, Jessica Beard and Francena McCorory crossed the line in three minutes 18.09 seconds, with Jamaica holding off Russia to take the silver medal.
Richards-Ross, who finished a disappointing seventh in the individual 400 final, staked the United States to a good lead on the first leg and they were never threatened.
"It was a great team effort and I'm really happy to represent the United States," Richards-Ross said.
The gold was also the first of the competition for Felix, who had been targeting an unprecedented world 200-400 double but had to settle for silver and bronze.
Britain's squad of Perri Shakes Drayton, Nicola Sanders, Christine Ohuruogu and Lee McConnell were fourth in 3:23.63.
Olympic 400m champion Ohuruogu said: “We knew it was going to be tough today. It’s disappointing because we have won medals twice with a similar team in 2005 and 2007 so we are just waiting for that medal to come back our way. Credit to the girls they did well.”
Russian Anna Chicherova finally clinched the women's high jump gold medal on a countback from Blanka Vlasic to end the Croatian's four-year reign as world champion.
Both Chicherova, who won silver behind her rival at the last two world championships, and Vlasic jumped 2.03 metres to move clear of the rest of the field but neither could clear 2.05.
Vlasic's failed attempts at 2.00 and 2.03 then proved decisive and the 27-year-old, who has been struggling with a knee injury and poor form this year, took silver.
Chicherova said she had been nervous after developing a cough on Saturday morning and feeling that perhaps her chance of a first major title might slip away again.
"My first thought in the morning was: 'Why everything is okay until the crucial moment comes and then always something happens?'," said the 29-year-old.
"I was angry with myself. That was also the reason why I could not make my best in the competition...I felt, like I still have to carry a heavy load behind me while jumping."
Croatian Vlasic, last year's International Association of Athletics Federations' women's athlete of the year, has spoken the past of having to deal with what she describes as "demons" when she is struggling, but was happy with her performance.
"I did not make it easy for them today," said the Olympic silver medallist, who also lost the title in Beijing on countback. "Of course, I am disappointed I did not win. It was a good competition and I am glad that my injury did not get worse here."
"Twenty days ago I was jumping 1.90 in training and I was crying like hell, I was, like, I don't want to put myself through this," she added.
Antonietta Di Martino won bronze for Italy's first medal of the championships after clearing 2.00 at her third attempt despite feeling tired after qualifying in the blazing Daegu sunshine.
"I started to feel my legs at 1.97, especially in my thighs," said the 33-year-old.
"It was difficult. I was just unsatisfied with clearing it on my third attempt. I got nervous because judges did not make up their mind on when I could jump.
"I was convinced I could jump well today. If my legs failed, my mind would respond."