Worthington, who started competing in 2016, crash landed in her first run but produced a stunning 360 backflip in her second -- the first to be landed by a woman in competition -- to edge American favourite Hannah Roberts.
However, there was heartbreak for Zharnel Hughes in the 100m final after a false start saw him disqualified from the race.
The 26-year-old was the first British man to qualify for the 100m final since Sydney 2000. The race was won by Italy's Lamont Marcell Jacobs.
"It's kinda unreal, I'm waiting to wake up. I've been dreaming about this for four years, and it still feels like I'm dreaming four years ago, I'm still waiting to wake up," Worthington said.
"It was incredible. I've not been doing that trick [the 360 backflip] for that long, we've been trying to find that big banger trick and when we found it we thought, 'this is the one'."
Later on Sunday, Whitlock claimed gold in on the pommel horse, defending his Rio 2016 title and winning his third individual Olympic title.
The 28-year-old took to the apparatus first, scoring an immense 15.583. He then had a nervous wait as the seven other finalists stepped up to the pommel, but his score went unmatched.
Whitlock became just the fourth artistic gymnast to defend their Olympic title.
Worthington's teammate, Declan Brooks, took bronze in the men's BMX freestyle, just two months after being left unconscious by a crash that threatened his Olympic dream.
"I've just cried for the past couple of minutes," Brooks said. "It's an unbelievable journey I've had on the way here, I'm just so stoked to win a medal."
Team GB had never won a BMX medal at the Olympics before Tokyo but will take away four after Sunday's event, with Worthington and Brooks' medals being added to Beth Shriever's gold and Kye Whyte's silver in BMX racing.
Meanwhile, Duncan Scott became Britain's most decorated Olympian at a single Olympic Games after GB's swimmers took silver in the men's 4x100m medley relay.
Luke Greenbank, Adam Peaty and James Guy made up the remainder of the team that broke the European record to claim second place.
"I'm very fortunate to be part of some excellent relay teams, this being one of them. Initially, we were very disappointed but since 2015, when we first started coming together, we've got back-to-back Olympic silvers in this event and we'd have taken that all day," Scott said.
"Looking at the splits, we all swam well. I'm slightly disappointed with mine but it has been a tough week and we have to be happy with that."
In boxing, Ben Whittaker and Pat McCormack are both guaranteed silver after winning their semifinal bouts.
Whittaker beat Russia Olympic Committee's Iman Khataev 4-1 in the men's light-heavyweight competition, while McCormack moved into the men's welterweight final after Ireland's Aidan Walsh withdrew from their bout.
British super-heavyweight Frazer Clarke is also guaranteed a medal in the ring after his opponent, France's Mourad Aliev, was disqualified in their quarterfinal for headbutting.
Look at that smile! 😁@BigFrazeBoxer becomes @TeamGB's fifth #Tokyo2020 boxing medallist. 🇬🇧🥊— GB Boxing (@gbboxing) August 1, 2021
He advances to the semi-final with a 🥉 secured, but with 🥇 still very much the aim! 🙌#TeamGB#TeamGBBoxing pic.twitter.com/ZeuWu5SmQj
Following the disqualification, Aliev staged a sit-down protest on the edge of the ring but returned to the changing rooms after 30 minutes.
Team GB's Paul Casey missed out on bronze in the men's golf after losing in a seven-man playoff for third, which included Ireland's Rory McIlroy and America's Colin Morikawa.
American Xander Schauffele clinched gold after a tense final round, with GB's other representative, Tommy Fleetwood, finishing down in 16th.
The Olympic journey also ended for Team GB's men's hockey team, who were knocked out of the tournament in the quarterfinals after losing 3-1 to India.
Elsewhere, Team GB are in gold-medal position going into the final stages of the eventing following the dressage and cross country on Sunday.
In the individual competition, Oliver Townend sits in first but teammate Laura Collett is close behind in third.
Meanwhile, Olympic diving champion Tom Daley was spotted knitting in the stands of the Tokyo Aquatics Centre.