Omega Pharma - Quick-Step retained their men's world team time trial title after edging out Orica-GreenEdge by less than a second in a thrilling battle in Florence.
Driven on by world time trial champion Tony Martin, the Belgian squad stopped the clock on a flat 57.2km course in 1hr 4min 17.62sec, which was just 0.81 seconds faster than their Australian rivals.
Team Sky, who had Tour de France winner Chris Froome in their ranks, claimed the bronze medal after finishing 22.5 seconds down in 1hr 4min 39.46sec.
Omega Pharma - Quick-Step, the defending champions, had been faster than Orica-GreenEdge by 12 seconds at the first intermediate split and 14 seconds at the second, but then Orica-GreenEdge enjoyed a blistering third sector and had turned their deficit into a 1.45-second lead by the third time check.
Omega Pharma - Quick-Step then responded to retake the lead and although they had a 10-second going into the final kilometre, they wilted in the last few metres and hung on by the narrowest of margins.
Martin said afterwards: "The last intermediate time gap killed our morale a little bit, seeing the first gaps and then being down on Orica-GreenEdge going into the final kilometres. But we had sport directors in the car who built up our motivation again. Then we just gave everything, full risks in the last 10km. At the end, it was enough."
The race was held on the opening day of the UCI Road World Championships in Tuscany, which run until next Sunday.
Earlier in the day, Great Britain's Katie Colclough was part of the Specialized - lululemon squad that successfully defended its women's team time trial title.
The six-woman team triumphed on a flat, 42.8km course from Pistoia to Florence in 51 minutes 10 seconds, with the Rabo squad second, 1min 11sec adrift.
The British Wiggle Honda squad, which is backed by Sir Bradley Wiggins and included Olympic champions Dani King and Joanna Rowsell, was sixth, 2min 33sec behind.
Lizzie Armitstead's Boels - Dolmans team finished 3min 33sec down in 10th place.
1 Omega Pharma - Quick-Step, 1:04:16:81
2 Orica-GreenEdge, +0.81
3 Team Sky, +22.55
4 BMC, +1:02.71
5 RadioShack-Leopard, +1:17.53
6 Astana, +1:21.14
7 Cannondale, +1:28.74
8 Garmin-Sharp, +2:01.94
9 Saxo-Tinkoff, +2:14.17
10 Movistar, +2:31.03
1 Specialized - lululemon, 51:30
2 Rabo Women's Cycling Team, +1:11
3 Orica-AIS, +1:33
4 Rusvelo, +2:02
5 MCipollini Giordana, +2:18
6 Wiggle Honda, +2:33
7 Argos-Shimano, +2:50
8 Optum p/b Kelly Benefit Strategies, +3:03
9 Sengers Ladies' Cycling Team, +3:05
10 Boels - Dolmans, +3:33