Simon Yates won the Vuelta a Espana to complete a clean sweep of British victories in this year's Grand Tours.
The 26-year-old Michelton-Scott rider crossed the line safely in Madrid on Sunday to secure his first Grand Tour, with Spain's Enric Mas second and Colombia's Miguel Angel Lopez third.
Britons Chris Froome and Geraint Thomas won the Giro d'Italia and Tour de France respectively this year.
Elia Viviani claimed the 100km final stage of the Vuelta in a bunch sprint.
In a chaotic run-in, the Italian edged out world champion Peter Sagan and Giacomo Nizzolo for his third stage win of the race.
British riders have now won nine of the past 20 Grand Tours, a run that started when Sir Bradley Wiggins became the first Briton to win a Grand Tour with victory in the 2012 Tour de France.
Only twice before have riders from the same country won all three races in the same season, but this is the first time it has been done by different cyclists.
And Yates' victory will be the fifth Grand Tour triumph in a row for Britain, with Froome having also won last year's Tour and Vuelta.
"It's astonishing really," Yates said. "Growing up I was so accustomed to seeing the French, Italian and Spanish riders lead the way, so for myself, Chris and Geraint to all win a Grand Tour in the same year just shows how far the sport has come in this country.
"It's been an unbelievable day. I really just enjoyed the moment, I don't know what else you can do in those situations.
"When I turned professional I signed with the team and we had a really big ambition to win a Grand Tour and now we've achieved that. I put the hard work in, I persisted with the training and everything else that goes with it and now we're here."
Froome said it was the "perfect year for British riders". He added: "Simon has looked so strong over the last three weeks and it's great to see him take home the maillot rojo."
- Read more: How 'battle-hardened' Yates learned from bitter Giro experience
- Listen: BeSpoke podcast - Yates makes it a British Grand Tour clean sweep
How Yates won the Vuelta
After a solid opening time trial, so often his Achilles heel in stage races, Yates showed his intent on stage four - the first in the mountains. He had lost a few seconds on stage two but got them back and more by finishing eighth at the top of the Puerto de Alfacar to climb to third overall.
He took control of the red jersey in rather fortuitous fashion on stage nine. He had slipped 14 seconds behind Alejandro Valverde after the 38-year-old Spaniard won stage eight. But Yates finished ninth on a day when Ben King won out of the breakaway to move ahead of Valverde by one second and take the lead.
The jersey was lost on stage 12 in what appeared to be a planned move, with Yates saying his Mitchelton-Scott team "decided not to really chase anyone".
He reclaimed it with victory on the climb of La Camperona on stage 14. Though the margin was only a couple of seconds, with bonuses applied he opened up a lead of 20 seconds over Valverde and 25 on the Spaniard's Movistar team-mate Nairo Quintana.
The time trial on stage 16 threatened to be a stumbling block but Yates was the quickest of all the general classification contenders, taking another seven seconds out of Valverde.
His 25-second lead over the 2009 Vuelta champion may have looked in threat but fears of a Giro-style meltdown were quashed on stage 19 when he attacked on the final climb to beat Valverde by more than a minute.
And he increased his place at the top of the standings with another assured ride on Saturday's final mountain stage, finishing third as his nearest challengers cracked on the final climb.
Unprecedented success, backdrop of controversies
This has been an unprecedented period of success for British riders, but it has also come against a backdrop of controversies and suspicion.
Yates served a four-month ban in 2016 for failing a drugs test at Paris-Nice, which his then team Orica-GreenEdge put down to an "administrative error". It later transpired a doctor had failed to apply for a Therapeutic Use Exemption (TUE) for an asthma inhaler.
Yates said at the time: "Unfortunately, as a result of an honest mistake of my team doctor, whom I trusted wholeheartedly, there will now be a doubt cast over my name, my previous results and any future glories."
Froome, meanwhile, had been under investigation after more than the allowed level of legal asthma drug salbutamol was found in his urine.
The case was dropped in July by cycling's world governing body the UCI, with the World Anti-Doping Agency accepting there was no breach.
That came four months after a report by MPs said Wiggins and Team Sky had "crossed an ethical line" by using drugs that are allowed under anti-doping rules to enhance performance instead of just for medical purposes.
Rainbow stripes next for Yates?
Yates' next major race is at the Road World Championships, which take place in Innsbruck, Austria, from 23-30 September.
The men's road race - on Sunday, 30 September - is on one of the toughest ever courses - 265km with more than 5,000m of climbing at gradients up to 25%
Yates and twin brother Adam will compete for Great Britain in an eight-strong team.
Lizzie Deignan, in 2015, was the last Briton to pull on the famous rainbow jersey at a Road World Championships, with Mark Cavendish, in 2011, the last man to win the title.
BBC Sport will be covering the championships live on BBC TV, red button and online.
Stage 21 result:
1. Elia Viviani (Ita/Quick-Step Floors) 2hrs 21mins 28secs
2. Peter Sagan (Svk/Bora-Hansgrohe) Same time
3. Giacomo Nizzolo (Ita/Trek-Segafredo)
4. Danny Van Poppel (Ned/Team Lotto NL-Jumbo)
5. Marc Sarreau (Fra/Groupama-Fdj)
6. Jon Aberasturi Izaga (Spa/Euskadi Basque Country-Murias)
7. Simone Consonni (Ita/UAE Team Emirates)
8. Matteo Trentin (Ita/Mitchelton-Scott)
9. Tom Van Asbroeck (Bel/Team EF Education First-Drapac P/B Cannondale)
10. Ryan Gibbons (SA/Team Dimension Data)
1. Simon Yates (GB/Mitchelton-Scott) 82hrs 05mins 58secs
2. Enric Mas (Spa/Quick-Step Floors) +1min 46secs
3. Miguel Angel Lopez (Col/Astana Pro Team) +2mins 4secs
4. Steven Kruijswijk (Ned/LottoNL-Jumbo) +2mins 54secs
5. Alejandro Valverde (Spa/Movistar Team) +4mins 28secs
6. Thibaut Pinot (Fra/Groupama-FDJ) +5mins 57secs
7. Rigoberto Uran (Col/EF Education First-Drapac p/b Cannondale) +6mins 7secs
8. Nairo Quintana (Col/Movistar Team) +6mins 51secs
9. Ion Izaguirre (Spa/Bahrain-Merida) +11mins 9secs
10. Wilco Kelderman (Ned/Team Sunweb) +11mins 11secs