Pärson came in behind Austria’s Anna Fenninger and Slovenia’s Tina Maze taking silver to claim her place on the podium.
The medal is Pärson’s first in a world championship since she won three golds at Åre, Sweden, in 2007, giving her a total of 18 medals in her career having also stood on the podium six times at the Winter Olympic Games.
“Every medal is something different and I have great memories of each one, I have had a great career,” beamed the 29-year-old.
“I had to have a strong downhill, but I made two mistakes.”
“It was a bit tight in the slalom, but Anna had a really good run in the slalom and I’m glad she won.”
Anna Fenninger’s victory maintains the Austrian women’s domination at the world ski championships after compatriot Elisabeth Goergl won super-G gold on Tuesday.
“I can’t realise it yet,” said teary 21-year-old Fenninger.
“It was very hard, the slope was really bad. The snow kept springing up, but I just fought through.”
“I wanted to prove to everyone I could do it in the slalom.”
“When you say that to me (that I’m world champion), I can’t believe it. It still has to sink in.”
This was Fenninger’s first major title and having finished fourth in the morning’s downhill, her combined winning time was 2mins 43.23secs with Maze second at 0.09sec back and Pärson at 0.27sec.
This is Maze’s second silver at a world championships after she finished second in the giant slalom in Val d’Isère two years ago.
“I said that Anna would have a good run today, I had a feeling she could also do well in the slalom,” said Maze.
“I’m very happy with my second place.”
Swiss teenager Lara Gut was in contention for a top three place until she took a nasty fall and was sent tumbling down the Gudiberg piste.
Having been the fastest down the Kandahar downhill course in the morning, Goergl finished fifth, just over half a second away from her second medal of the fortnight-long championships.
Home favourite and overall World Cup leader Maria Riesch, the Olympic champion, ended up finishing 11th, having been 15th in the downhill, as she produced a battling performance to race despite the effects of a bout of flu.
“You have to accept these things,” said a disappointed Riesch, who won a bronze in the super-G.
“I did my best, but it wasn’t enough.”
“It is certainly troublesome to be sick, but I already have a medal.”
“I am going to train for the downhill tomorrow to work on the second part of the course where I lost a bit of time today.”
Struggling all week with the after-effects of a head injury, reigning world downhill champion Lindsey Vonn sat out the slalom, having been 12th fastest in the downhill, to focus on defending her title on Sunday.
“I am still not 100 percent fit, I won’t do the slalom, I couldn’t concentrate enough at the end of the race,” admitted Vonn.