An expert in the limited-overs game, he was one of the key cameo figures in Essex's 2005 domestic one-day league title winning season, having previously gained experience as an England Under-19 player, having played twice against India during their English tour of 2002.

Later the same month, against Leicestershire in the last match of the 2006 County Championship, he hit 114 not out from 29 balls, but this innings was made against "declaration" bowling and so was not eligible for the Walter Lawrence Trophy, nor did it count as a first-class record.

In June 2007, Pettini became permanent captain of Essex County Cricket Club following the retirement of Ronnie Irani due to a knee injury.

At the start of the 2008 season, Pettini decided to move from opener to number five in the Essex batting order in four-day cricket.

Pettini's form tailed off somewhat, but he did hit a match-winning 144 against the Surrey Brown Caps in a Friends Provident Trophy match at the Oval on 11 May 2008.

Pettini also wrote a weekly column called "Pett Sounds" in the Southend Echo and Colchester Gazette newspapers.