The Christie sisters took a superb gold to cap a historic first day for Great Britain at the ICF Wild Water World Championships in Spain.
The first of four days of action in Sabero was for the long-distance specialists battling for classic medals over a 5.8km course.
Kerry opened the day with a magnificent silver in the women's kayak classic, adding to the K1 silver she won at the junior and u23 Europeans last month.
“I was really pleased with all my lines – I think they were the best I've ever done them,” she said.
“I just pulled really, really hard. I was very, very pleased with the run.”
The silver medal was a first classic senior World Championship medal for Britain since Hannah Brown’s silver in 2010.
The day ended with Kerry and younger sister Emma becoming canoe double classic world champions, a first British world title since 2016, almost 12 months after they had taken the under-23 C2 world title.
“It feels so good,” said Kerry.
“We were four seconds down at the split so we had to really pick it up.”
A prolific season for 21-year-old Kerry just keeps getting better after five-medal hauls at both the opening World Cup event in June and the European Championships.
Having finished in last place in her only previous appearance at the senior World Championships, Christie came tantalisingly close to becoming senior world champion.
Stepping up to her biggest competition of the season, Christie produced a scorching run in the championship's curtain-raising event, the women's kayak classic.
An impressive 19min 29.44secs secured a brilliant silver, just 1.6 seconds behind French winner Claire Bren who herself narrowly missed out on Olympic selection.
Lucy Guest was the first paddler down the Esla River in the championship's opening event, and the Brit earned a fantastic top-10 finish, posting 19:47.97 for ninth place, one of only 13 paddlers in a 46-strong field to break the 20-minute mark.
Emma Christie forced her way into the top 20, racing her way to 19th in 20:17.30.
But more was to come for Emma who earned four medals at the U23 European Champs.
The Christie sisters were penultimate boat down in the women's canoe double and were guaranteed a medal when they knocked Laura Fontaine and Eve Vitali-Guilbert off top spot with a scorching time of 21min 03.54secs, just 3.7 seconds faster than the French duo.
All eyes were then trained on the finish of Swiss paddlers Mona Clavadetscher and Hannah Mueller, but when they stopped the clock 12 seconds slower, the gold belonged to Great Britain.
Laura Milne and Mags Dilai put in a good run to take fifth spot in 21:56.62, while European junior silver medalists Ciara Maloney and
Elsie Landsborough finished seventh in 22:22.09.
Earlier, Andrew Crowhurst built on some encouraging World Cup runs by finishing 20th in the men's canoe classic, clocking 21min 23.93secs.
Team-mate Ryan Mallon (CR Cats) went 27th quickest in a 34-strong field in 22:31.75.
Great Britain had four boats in a huge 77-man field for the day's third final – the men's kayak classic.
Leon Tomlinson (Nottingham Kayak Club) set the fastest pace of the GB quartet on his senior world championship debut.
The Nottingham Kayak Club paddler dipped under the 19-minute mark with 18min 52.38secs for 28th.
There was little to split Nottingham's Huw Singleton (19:11.86), also on his senior world championship bow, and Jacob Holmes (19:10.43), with the Breadalbane paddler nudging his team-mate into 35th place.
Sprint specialist Alex Sheppy, who won World Cup bronze over the shorter distance in June, negotiated the course in 19:51.30 for 47th.
Slovenian paddler Simon Oven denied France a kayak classic double by pipping silver medalist Maxence Barouh by just four-hundredths of a second.
Chloe Bracewell was GB's sole competitor in the women's canoe classic final, and posted a time of 23min 38.33secs to finish 13th.
Britain had a trio of boats in the men's canoe double, and for a time glory beckoned.
The Scottish pair of Rob Jefferies and Jacob Holmes hit the top of the timesheets when they stopped the clock in 21min 08secs dead.
Their lead lasted less than a minute, replaced by team-mates Andrew Crowhurst and Phil Dean with 20:57.23, and when Fred Brown and Nick Boreham came home in 21:18.05, Great Britain filled all three podium places.
Yet with 15 of the 25 boats still to come, the British boats eventually finished in 11th, 12th and 13th respectively.
There will be plenty of British interest on day two as the championships move on to the team classic finals.
Results –
Women's K1: 2nd – Kerry Christie 19:29.44; 9th – Lucy Guest 19:47.97; 19th – Emma Christie 20:17.30
Men's C1: 20th – Andrew Crowhurst 21:23.93; 27th – Ryan Mallon 22:31.75
Men's K1: 28th – Leon Tomlinson 18:52.38; 34th – Jacob Holmes 19:10.43; 35th – Huw Singleton 19:11.86; 47th – Alex Sheppy 19:51.30
Women's C1: 13th – Chloe Bracewell 23:38.33
Men's C2: 11th – Andrew Crowhurst/Phil Dean 20:57.37; 12th – Jacob Holmes/Robert Jefferies 21:08.00; 13th – Fred Brown/Nick Boreham 21:18.05
Women's C2: 1st – Kerry Christie/Emma Christie 21:03.54; 5th – Laura Milne/Mags Dilai 21:56.62; 7th – Ciara Maloney/Elsie Landsborough 22:22.09