"I'm in the best shape I've ever been in and I've had a great winter," said the Team Sky rider, after he failed to beat Sweden's Gustav Larsson by just one second in the 9.4-kilometre (5.8-mile) time-trial here.
Wiggins started this season with a third-place finish in the Tour of the Algarve, which he said had left him "raring to go", particularly with a chance to defend his Olympic titles in front of a home crowd in London.
The Londoner, who was third in last year's "race to the sun", was one of the last to go on the course and looked likely to have beaten Larsson if the heavens hadn't opened in the last half-hour of the race.
Wiggins admitted he could have gone faster but fared a lot better than the two German riders who beat him on the podium in 2011: defending champion Tony Martin was 24 seconds behind the Briton, while Andreas Kloeden lost 35 seconds.
"I didn't take any risks in the corners but I knew in a straight line I was flying," he said. "I wasn't willing to find out whether it was slippery so I never really pushed it as hard as I could have done in the corners.
"I'd already slipped on the ramp coming off the start, so straight away I had one mind on safety in the corners. Fortunately, there weren't so many corners so it wasn't as decisive."
Wiggins clawed his way back from 14th position at 1.8 km, five seconds behind the best time but was faster than Larsson in the final part of the course.
Larsson, 31, has not won a major title but has carved out a reputation for himself when up against the clock.
In 2008, he won a silver medal in the Beijing Olympics behind Fabian Cancellara of Switzerland.
"It's my second race of the season and I didn't expect to do as well," said Larsson who quit Bjarne Riis' Team Saxo Bank to join the Dutch outfit Vacansoleil.
The big Swede rode at nearly 50 kilometres (31 miles) per hour to steal a march on a number of big names.
Spain's Alejandro Valverde, who set off on a dry course, was 30 seconds back, one more than his compatriot Luis Leon Sanchez, who won the race in 2009.
Three younger riders showed their potential: America's Tejay Van Garderen, who was fourth, was nine seconds behind Larsson; Estonia's Rein Taaramae (7th) was at 13 seconds; while Jerome Coppel (10th), was at 15 seconds.
Monday's stage in theory favours the sprinters, with 185.5 kilometres on the flat between Mantes-la-Jolie west of Paris and Orleans. But blustery conditions are expected.
