The Team Katusha rider, the Italian national champion, just edged out Thomas Voeckler in a thrilling sprint finish on stage 12 with Australian Richie Porte hanging on to the leader's pink jersey for Saxo Bank.
Driving rain on Wednesday led to a huge turnaround in the overall placings with Porte taking charge and previous leader Alexander Vinokourov sliding down the standings after being caught in a slow group as the weather-beaten peloton split.
World champion Cadel Evans, who had been second overall, was also punished by Wednesday's events and his frustration was plain to see on the 206 km uncomplicated stage from Citta Sant'Angelo to Porto Recanati on central Italy's east coast.
The BMC rider argued with other riders about the lack of pace at the front of the pack late on and gesticulated wildly.
The stage lead had changed hands numerous times amid an array of breakouts but the main block of riders was never far behind.
However, an exciting climax did ensue with Pozzato timing his burst just right having already had a good look at the finish during an earlier loop through Porto Recanati.
"I'm very happy, it's what we needed. We had to have a stage like this after yesterday," Pozzato told reporters.
"The last week will be spectacular and it won't be over till it's over."
Unheralded Porte's overall lead from Spain's David Arroyo is one minute 42 seconds.
A raft of riders quit the race after Wednesday's extremely tough outing, one of a number of demanding and wet stages already this year, but the pain is not over yet with two big mountain tests due this weekend.
Friday's 13th stage is a 223 km trip from Porto Recanati to Cesenatico.
The three-week race ends in Verona on May 30.
Meanwhile, disgraced Tour de France winner Floyd Landis has confessed to using performance enhancing drugs and accused some of the biggest names in the sport, including Lance Armstrong, of also cheating.
Landis, who was stripped of his win the 2006 Tour de France after failing a doping test, had always protested his innocence but said he had finally decided to come clean.
"I want to clear my conscience," Landis told ESPN on Thursday after making his confession in a series of emails.
"I don't want to be part of the problem any more."
In the emails, which Reuters has seen and Landis said were also distributed to USA Cycling and the International Cycling Union (UCI), the American provided implicit details of a variety of drugs he had used during his career and who supplied them to him.
He said he witnessed a number of other top riders also using performance enhancing drugs, including his former team mate Armstrong, a seven-time winner of the Tour de France.
Armstrong has never failed a doping test and has always maintained his innocence despite years of accusations.
He was not immediately available for comment but was expected to face the media after Thursday's fifth stage of the Tour of California.
Anti-doping officials said they would investigate Landis' accusations.
"We are very interested in learning more about this matter and we will liaise with the United States Anti-Doping Agency (USADA) and any other authority with appropriate jurisdiction to get to the heart of the issues raised," World Anti-Doping Agency (WADA) president John Fahey said in a statement.
In his emails, Landis accused UCI officials of covering up an alleged positive test from Armstrong.
UCI president Pat McQuaid responded by questioning Landis's credibility.
"After going through two or three court cases denying everything, the question is what credibility does he have?" McQuaid told Reuters.
Landis was stripped of his win in the world's most famous race after returning an abnormal testosterone/epitestosterone ratio.
He denied any wrongdoing and fought a long legal case, which he eventually lost, and was banned for two years.
When his suspension ended last year, he hinted at making a return to the Tour de France in 2010 but in February a French judge issued an arrest warrant against him for suspected hacking into an anti-doping laboratory computer.
French anti-doping agency head Pierre Bordry said the judge, Thomas Cassuto, believed Landis wanted to prove the laboratory where his samples were tested was wrong.
