A late change of bike could not prevent Tony Martin from claiming Stage 4 of the Tour de France to assume the yellow jersey from Chris Froome.
The Etixx-Quick Step rider made a bold break with just under four kilometers to go, wiping out the one-second deficit to previous leader Froome of Team Sky.
MORE: Tour de France 2015 in photos | Stage 4 results, leader, overall standings
Victory also handed the German a 10-second bonus to strengthen his position, though the former world time-trial champion is not likely to be able to compete when the Tour hits the mountains.
With the race having been rocked by a dramatic Stage 3, in which a huge crash ultimately caused five riders — including general classification (GC) contender Fabian Cancellara (Trek Factory Racing) — to abandon the Tour, Tuesday's 223.5-km route from Seraing to Cambrai provided more drama.
Although there were no major casualties, the cobbled sections played havoc as numerous riders suffered mechanical failures.
Indeed, Martin had to switch bikes late, but was faithfully guided back to the leading pack by his teammates before surging clear to finish ahead of John Degenkolb (Team Giant-Alpecin) and Peter Sagan (Tinkoff-Saxo).
The main GC hopefuls emerged from the stage unscathed, with Froome, Vincenzo Nibali (Astana), Nairo Quintana (Movistar), Alberto Contador (Tinkoff-Saxo) and American Tejay van Garderen (BMC Racing Team) all safely nestled in the pack.
Froome will have been particularly relieved, having survived a wobble when he was barged into midway through, given that his title defense was ended by injury on the cobbles last year.
An early four-man break was largely ignored to begin with, allowing Lieuwe Westra (Astana), Thomas De Gendt (Lotto-Soudal), Perrig Quemeneur (Europcar) and Frederic Brun (Bretagne-Seche Environnement) to take the top four spots at the intermediate sprint.
Mark Cavendish (Etixx-Quick Step) was next to cross for 11 points, closing the gap on green jersey holder Andre Greipel (Lotto-Soudal).
The race entered France for the first time this year with 83 kilometers to go and immediately saw a minor tangle involving Stage 2 winner Greipel, which forced him and a few other riders to drop behind.
A restless Sagan encouraged fellow speed kings Cavendish and Greipel to build on the gap that had opened up over the pack in the bid for intermediate sprint points as the race stepped up a gear.
By the time of the second cobbled section, the gap was just 30 seconds, and by the third the lead group had been swallowed by the peloton.
That set the race up for the final stretch into Cambrai, which offered plenty of talking points as FDJ.fr's Thibaut Pinot was one of several to suffer a mechanical failure.
His response was one of petulance, directing his ire at a team mechanic, while Martin was led back to the front and did the rest from there in an explosive finish from the 30-year-old.