SO CLOSE: Alessandro Petacchi (centre) edges out Julian Dean (second left) during the fourth stage. APCYCLING Alessandro Petacchi, of Italy, edged out New Zealander Julian Dean to win the fourth stage
The Lampre rider collected his second-stage win this Tour in the 153.5km ride from Cambrai to the champagne capital Reims - a mostly flat trek that appeared tailor-made for sprinters.
Petacchi, competing in his first Tour since 2005, veered out wide left to get a jump on three lead riders with a few metres left, and pedaled furiously to hold them off at the finish.
He edged Kiwi Dean into second, and Edval Boasson Hagen of Norway was third.
The pack had the same time as Petacchi: 3 hours, 34 minutes, 55 seconds.
"I'm really happy ... I had nothing to lose, and I wanted to try my chances," said Petacchi, who also won four stages in the 2004 Tour.
"At this stage in my career, winning two Tour stages is really important."
Defending champion Alberto Contador was 32nd, last year's runner-up Andy Schleck placed 58th, and seven-time champion Lance Armstrong crossed 36th.
Fabian Cancellara of Switzerland retained the yellow jersey, having recovered it during yesterday's ride over cobblestones - where Armstrong sustained a punctured tyre and lost precious seconds.
The other top standings didn't change.
Among the overall contenders, two-time Tour runner-up Cadel Evans is third, 39 seconds back, Schleck is sixth, 1:09 back, Contador is ninth, 1:40 back, and Armstrong is 18th, 2:30 back.
Before the stage, Armstrong said he would need to be "opportunistic" in a bid to make up ground in the race, that ends July 25 in Paris.
The next big challenges loom in the Alps in Sunday's Stage 8.
The Saxo Bank rider will take no further part.
 Fourth stage result:
1. Alessandro Petacchi, Italy, Lampre-Farnese, 3 hours, 34 minutes, 55 seconds.
2. Julian Dean, New Zealand, Garmin-Transitions, same time.
3. Edvald Hagen Boasson, Norway, Sky Pro Cycling, same time.
4. Robbie McEwen, Australia, Katusha Team, same time.
5. Robert Hunter, South Africa, Garmin-Transitions, same time.
Overall Standings:
1. Fabian Cancellara, Switzerland, Team Saxo Bank, 18 hours, 28 minutes, 55 seconds; 2. Geraint Thomas, Britain, Sky Pro Cycling, 23 sec behind; 3. Cadel Evans, Australia, :39. Reuters