With 65 percent of precincts reporting, Christie had 60 percent of the vote to Democratic state Sen. Barbara Buono's 39 percent.
He was expected to become the first Republican in a quarter-century to receive more than 50 percent of the New Jersey vote. This, in a state that President Barack Obama carried a year ago by more than 17 points, his biggest margin in the nation.
Buono told supporters in her hometown of Metuchen, on the fringes of the New York area, shortly after polls closed that she had called Christie to congratulate him. She noted they had their differences but added, "when it comes down to it, we're just two parents who want to see the best for our children's future."
Christie performed strongly across the political spectrum. Interviews with voters as they left polling places found Christie re-elected with broad support among whites, independents, moderates, voters over 40 and those opposing the health care law, among others.
He did well among groups that typically lean Democratic, carrying a majority of women and splitting Hispanics with Buono. And Christie improved on his share of the vote among blacks in 2009 by more than 10 percentage points.
The interviews were conducted for the AP and television networks ABC, CBS, NBC, CNN and Fox News by Edison Research.
Backed by soaring approval ratings for his leadership after Superstorm Sandy, the tell-it-like-it-is governor built a winning coalition by aggressively courting constituencies that often shun the GOP: minorities, women and even Democrats, who outnumber Republicans among registered voters by more than 3 to 2.
Christie, who is openly considering running for president, has said his success offers a template for broadening the GOP's appeal after the disastrous 2012 election cycle and the party's record-low approval ratings following the recent government shutdown. Christie will take over later this month as chairman of the Republican Governors Association, a position that will further raise his national profile.
Christie becomes his party's biggest winner on a night in which Democrat Terry McAuliffe was elected Virginia's next governor, defeating conservative firebrand Ken Cuccinelli. Christie, in contrast, painted himself as a pragmatic leader who worked with Democrats to get the job done during his four years in office.
It was a picture that largely went unchallenged during an election that was never really in doubt.
The Obama administration declined to deploy its best political weapons against Christie, while Buono struggled to earn the support of her party's most devoted supporters. The Democratic Governors Association spent less than $5,000 on the contest while pouring more than $6 million into the Virginia election.
"The Democratic political bosses, some elected, and some not, made a deal with this governor, despite him representing everything they are supposed to be against," Buono said in her concession comments.
Christie built a national fundraising network, dramatically outspending Buono on the airwaves and improving his organization beyond New Jersey. The Christie campaign spent $11.5 million on TV and radio ads, compared with Buono's $2.1 million, according to SMG Delta, a Virginia-based firm that tracks political spending.
Buono repeatedly tried to use Christie's presidential ambitions against him, accusing him of putting his interests ahead of New Jersey's.
She supported gay marriage and abortion rights, while Christie opposes both. When it became clear last month that the New Jersey Supreme Court would rule in favor of gay marriage, Christie dropped an appeal, allowing the practice to become legal in the state.
During a debate less than a month ago, Christie admitted he might not serve out his full second term should he launch a White House bid.
"I won't make those decisions until I have to," he said.
Facing a skeptical moderator, he replied in the usual blunt, you-gotta-be-kidding-me manner that has proved appealing to voters of both parties: "I can walk and chew gum at the same time. I can do this job and also deal with my future."
Christie, 51, was already popular when Sandy slammed into the coast a year ago, damaging 360,000 homes and businesses and plunging 5.5 million people into darkness. His popularity soared as he donned a blue fleece pullover and led the state through its worst natural disaster, whether embracing Obama or consoling a tearful 9-year-old who had lost her house.
He also underwent weight-loss surgery in February and has been shedding pounds steadily since, a step that could dispel some of the health concerns that have hung over his political future.
Christie's bipartisan appeal does not sit well with GOP conservatives, who are the party's most passionate voters and wield outsize influence in Republican presidential politics. But in a Tuesday interview with CNN, even before his victory was official, Christie appeared to be looking ahead.
Asked if he was a moderate, Christie used a word rarely uttered on the campaign trail in recent days: "I'm a conservative," he said.
"I've governed as a conservative in this state, and I think that's led to some people disagreeing with me in our state," he continued. "The difference has been is I haven't tried to hide it or mask it as something different."
Contributing to this report were Associated Press Director of Polling Jennifer Agiesta in Washington and AP writer Bruce Shipkowski in Metuchen, N.J.