Looking to erase what polls say is a deficit of 8 to 9 percentage points, Deeds hammered McDonnell as no friend of working women and called him out on what he said were lies about his energy and tax proposals.
"I guess he wants this campaign to be decided on the issues he's going to lie about," Deeds said in the only prime-time debate to be televised live in every Virginia market.
The first time Deeds accused him of lying came minutes into the debate, in a discussion of the economy, when McDonnell claimed Deeds had backed $3.5 million in new taxes as a legislator and planned to impose $1 billion in new taxes if elected.
The claim was a reference to McDonnell's presumption that Deeds would boost fuel taxes by about $1 billion annually to meet a backlog of unmet road construction needs transportation officials now estimate to approach $100 billion. It's no more than a presumption because Deeds has steadfastly refused to detail how he would raise transportation revenue.
Midway through the debate, Deeds accused McDonnell of lying again in claiming that he supports President Barack Obama and a Democratic Congress on the cap-and-trade energy bill that would increase costs for each Virginia household by about $1,700 a year.
"Bob continues to talk about the cap-and-trade bill and he's spending literally millions lying to voters of Virginia about it," Deeds said midway through the hourlong debate. "Factcheck.org has also called him on that and said it's just not true."
Did Deeds go too far accusing a political rival of lying? Less than a month after U.S. Rep. Jim Wilson, R-La., was excoriated for yelling "You lie!" as Obama addressed a joint session of Congress on health care reform policy last month.
"I think we need more civility in politics and I don't think we need name-calling," McDonnell told reporters after the debate. "I found that to be really below the dignity of a gubernatorial campaign for Creigh to say that. I'm sure he's probably not happy he said that tonight."
Deeds was unbowed.
"Maybe that wasn't the best use of words. But the fact is, it's not true," he said, refusing to apologize. "I guess if you say it enough times, that doesn't make it any more true than it was the first time."
The issues of taxes, transportation, energy policy and rights of gays and women dominated the third of four debates and the only one carried by stations in every market statewide.
Deeds took the offensive early on the gender issue as both candidates pledged to continue an executive order mandating equal pay for male and female state government workers.
"Women constitute 54 percent of our population, government should look like the people we represent," Deeds said, pledging that half of his cabinet would be women.
Deeds quickly flagged the thesis McDonnell wrote at age 34 for a master's and law degree at Christian Coalition founder Pat Robertson's Regent University, the school's pro-male hiring policies and McDonnell's vote in 2001 against a resolution calling for equal pay when he was a member of the House of Delegates.
"I've been married to a working woman for 33 years," McDonnell countered. "My oldest daughter was a platoon leader in Iraq when Creigh and I ran against each other a couple of years ago, and I'd say that's the ultimate working woman."
Deeds said he would also renew an executive order protecting gays who work for state government from discrimination. McDonnell said he was opposed to the order on constitutional grounds, claiming it was properly the General Assembly's call.
The sharp tone of the debate reflects the stakes for in an election viewed as an early voter verdict of Obama and Congress.
Virginia and New Jersey are the only states electing governors this fall and Gov. Timothy M. Kaine, Obama's choice as Democratic National Committee chairman, has pledged at least $6 million to his home state to keep the GOP from winning his seat for the first time in eight years.
Deeds entered the debate needing a breakout moment.
As Democrats struggle to energize black voters and women -- key components of any winning Democratic campaign -- polls by The Washington Post and by Mason-Dixon Polling and Research Inc. over the past week showed McDonnell with a solid lead and faring much better among independent voters than Deeds.
The Post poll showed that the thesis ranked low among voters' concerns heading into the Nov. 3 election.
The League of Women Voters and AARP sponsored the debate.