With 95 percent of precincts reporting Wednesday, Lieberman had 50 percent of the vote to Lamont's 40 percent. Lieberman, a conservative Democrat who backed U.S. President George Bush on Iraq, won re-election with Republican support and a $17.5 million campaign war chest, the Hartford (Conn.) Courant said.
Lamont, 52, spent nearly $16 million of his personal fortune in his first political race.
"I'm Joe Lieberman and I approve of this election," Lieberman, 64, beamed to a crowd at the Goodwin Hotel in Hartford.
Lieberman called his re-election "a declaration of independence from the politics of partisanship."