Great Britain's cyclists made the perfect start to five days of track racing when Chris Hoy, Jamie Staff and Jason Kenny won gold in the team sprint.
The British trio saw off France, to whom Staff and Hoy had lost in the final at March's World Championships.
Great Britain hit the finishing line in a time of 43.128 seconds, more than half a second faster than the French (43.651).
Germany took the bronze medal bronze with a time of 44.014, relegating Australia (44.022) to fourth place.
Staff led off the trio and said: "It hasn't sunk in yet, it's weird, but mostly exciting.
"We were very disappointed after Athens (finishing fifth). I've given absolutely everything I could into it and it paid off.
"We've got a fantastically strong team, we showed everyone at the worlds how strong we are."
Hoy, who also has his sights set on gold in the keirin, added: "To win as part of a team is a totally different feeling (from the 1km time trial in Athens) Our friendship has been so dominant in the last few years.
"As part of a team, you can't let anyone down.
"To beat them by half a second made it that exciting. Honestly, it took every inch of effort in beating the French who have been invincible.
"The French have been so dominant. We have really put all the pieces of the jigsaw together. We really focused on the details.
"To stick half a second into them, it's amazing."
Hoy insists he still he is hungry for more glory at the Games and has his sights set firmly on a trio of golds.
He said: "There's still plenty in the tank.
"At the end of the week, if I get three (keirin and men's sprint), I'll do a dance for you and that's a promise."
The Scot reserved special praise for 20-year-old Kenny, adding: "He's young and talented and not fazed by the pressure at all, he's perfect for the team."