"Sadly, Jon Corzine now joins that long list of politicians who overpromised and underdelivered," Christie said in accepting his party's nomination.
Corzine, who glided to victory in the Democratic primary after facing only token competition, officially kicked off his re-election campaign with Vice President Joseph Biden in West Orange.
"Barack Obama and Joe Biden are committed to Jon Corzine's re-election. Period. End of sentence," Biden said. "We need Jon Corzine at the helm."
In accepting the party's nomination, Corzine said being governor was "the highest honor of my life."
"Serving the people," he said, "is my highest calling."
Corzine, 62, faces a tough re-election bid. Several polls have shown him trailing Christie, a former U.S. attorney under former President George W. Bush.
Christie was enthusiastically backed by the state's Republican establishment, receiving virtually every county GOP endorsement. He is widely viewed within the party as the only candidate with a shot at recapturing the governor's office, which no Republican has done since Christie Whitman won a second term in 1997.
Even before the primary polls closed Tuesday night, Christie's daughter, Sarah, 13, was ready to proclaim her dad the nominee, holding a homemade posterboard sign that read: "CJC Victory."
Christie opponents Steve Lonegan and Assemblyman Rick Merkt said they will support the nominee in November, though Lonegan has said he will try to push Christie to the right on economic issues.
That could be significant in a state with more registered Democrats than Republicans and even more unaffiliated voters.
"The most important thing," said state Sen. Bill Baroni, R-Hamilton, "is that we wake up tomorrow as a united Republican Party."
With only two governor's races in the country this November - the other is in Virginia - the New Jersey contest is being closely watched. National Democratic and Republican groups already have poured money into attack ads.
Christie faces an uphill battle against the far wealthier Corzine. Because he is accepting public financing, Christie is bound by a $10.9 million spending limit. Corzine, who is funding much of his own campaign, is not.
In the lone GOP Senate race in the 23rd District, Assemblyman Michael J. Doherty defeated incumbent Sen. Marcia Karrow.
MORE POLITICS FROM AP
NEW YORK AND TRI-STATE AREA NEWS
E-MAIL UP CLOSE || REPORT TYPO || GET WIDGET
UP CLOSE ON FACEBOOK