Sir Bradley Wiggins missed out on a first road world title as Germany's Tony Martin took a third consecutive time trial gold with a commanding ride in Florence.
Wiggins, 33, overhauled Switzerland's Fabian Cancellara in the final third of the 57.9km course to win silver - as he did in the 2011 Championships.
But Martin had built a lead from the start and came in 46.09 seconds ahead.
"I knew it would be close but Tony was on a different level," said Wiggins.
"I just aimed to be the quickest from A to B as possible.
"Performance manager Rod Ellingworth was telling me the checkpoints but, with all the noise in the last 20 minutes, I was oblivious to everything, and was just trying to get home.
"It is an honour to be on the podium with those two guys. It will be something to show the grandkids."
After his Giro d'Italia campaign faltered amid crashes and illness and fellow Briton Chris Froome supplanted him as Tour de France champion, Wiggins had hoped to crown a strong finish to the year before his return to track cycling next season.
The 33-year-old completed a commanding victory in the Tour of Britain on Sunday, but ultimately Martin's power and his experience of the Florence course, gained during Omega Pharma-QuickStep's team victory earlier in the event, proved too great to overhaul.
Wiggins had beaten Martin en route to time trial gold at London 2012, but, having recovered from the fractured scaphoid that disrupted his Olympic preparation, the German was always in command of the race.
Martin had a lead of 13 seconds on Cancellara through the first checkpoint at 24.1km and extended that advantage to 28 seconds by 42.3 km.
While Wiggins eventually overhauled Cancellara, Martin remained well out of reach and his jubilant team started celebrating as he entered the home straight.
Three-time British time trial champion Alex Dowsett had beaten Wiggins in the Giro d'Italia time trial, but had been well off the pace in the corresponding Tour of Britain stage last week, and struggled home in 41st.
The rest of the top five was completed by Wiggins' Team Sky colleague Vasili Kiryienka of Belarus and American Taylor Phinney.
British Olympic silver medallist Lizzie Armitstead will attempt to go one better in Saturday's women's road race, before Froome, supported by Wiggins, leads Britain's charge in the men's race on Sunday. Both are live on BBC television and online.
Time trial result:
1. Tony Martin (Ger) 1:05:36.65
2. Bradley Wiggins (GB) at 46 seconds
3. Fabian Cancellara (Swi) at 48"
4. Vasili Kiriyenka (Bel) at 1:26"
5. Taylor Phinney (USA) at 1:08"
13. Nicolas Roche (Ire) at 3:13"
41. Alex Dowsett (GB) at 5:47"