Brent Bookwalter extended his overall lead of the Tour of Qatar after his BMC team produced a superb display to claim victory in stage two's 14km team time trial.
Team Sky looked to have sewn the win up with a tactically astute ride that knocked five seconds off Omega Pharma - Quick-Step's previous best time.
But then BMC shed three men in the final kilometre and left their five strongest riders to power them over the line in a time of 16 minutes seven seconds.
The result means Bookwalter, who sprinted to victory on stage one on Sunday, stretches his overall lead to six seconds, with team-mate Taylor Phinney moving into second place and British rider Adam Blythe, also of BMC, third a further four seconds back.
Team Sky will still be pleased with their performance and now occupy places six to ten in the general classification.
Asked if he could now go on to win the race, Bookwalter said: "One day at a time. Anything can happen here with the wind. One minute you are in control, the next it is blown to pieces.
"We are going to enjoy today and get back on it tomorrow. It's a really strong field and it's still pretty close."
Astana were the fastest team of the earlier starters with a time of 16min 24secs, but some of the smaller outfits in the field struggled on the Al Rufaa Street course.
Newly formed IAM Cycling had particular trouble on one corner, when their riders somehow separated themselves on to different sides of the road and had to ride in two groups until they could rejoin at the next junction.
RadioShack-Leopard returned order to the race as they assumed the lead in 16min 18secs, but they were soon overhauled by an Omega Pharma Quick-Step team for whom Mark Cavendish made a strong contribution and was among their first group of riders over the line.
Sky opted for a ball-shaped formation to combat Qatar's strong winds and finished in a group of six including Edvald Boasson Hagen and Britons Geraint Thomas and Luke Rowe.
However, BMC were last out and, driven on by time-trial expert Phinney, they eclipsed Sky's time to take their second victory of the race.
Bookwalter added: "You felt everyone of those 14km like it was 20. The team was just incredible. I'm beside myself. I think it was all for one, one for all today.
"[Phinney] really led us well today, not just with his pulls but with his leadership. We are going to enjoy today - it was a big team effort - and we will come back out to do it again."
1 BMC, 16min 07secs; 2 Team Sky, +5secs; 3 Omega Pharma - Quick-Step, +10; 4 RadioShack-Leopard, +11; 5 Katusha, +15; 6 Astana, +17; 7 Orica-GreenEDGE, +23; 8 FDJ, +23; 9 Cannondale, +24; 10 Saxo-Tinkoff, +26
1 Brent Bookwalter (USA) BMC, 3:44.44; 2 Taylor Phinney (USA) BMC, +6secs; 3 Adam Blythe (GB) BMC, +10; 4 Greg van Avermaet (Bel) BMC, +10; 5 Michael Schar (Sui) BMC, +10; 6 Bernhard Eisel (Aut) Team Sky, +11; 7 Edvald Boasson Hagen (Nor) Team Sky, +15; 8 Geraint Thomas (GB) Team Sky, +15; 9 Mathew Hayman (Aus) Team Sky, +15; 10 Luke Rowe (GB) Team Sky, +15; 11 Mark Cavendish (GB) Omega Pharma - Quick-Step, +20