The overflow audience quieted when Kennedy, whose personal life has been the topic of much debate, was asked to name his greatest personal failing.
Although Kennedy admitted that he "had not lived up to all the expectations of the people in Massachusetts," he said his 1992 marriage to Washington lawyer Victoria Reggie, has changed him.
Romney answered the same question by saying he regretted not being able to spend more than one day a week helping people in the community.
"[My greatest personal failing] is my inability to fulfill my God-given obligation to help other people," Romney said.
After the debate, each side claimed victory, saying its candidate articulated his position and clearly emphasized his differences with the other.
"[Kennedy] was in command," Kennedy's campaign manager and nephew Michael L. Kennedy '80 said. "He was focused on the real issues."
"They both landed some punches tonight, but Sen. Kennedy clearly won the debate tonight," said the candidate's nephew, U.S. Rep. Joseph P. Kennedy II. "It was a very good night for Sen. Kennedy's campaign."
Romney's campaign officials said their candidate was calm and presented himself well to the state's voters.
"People saw a Mitt Romney who was smart, strong on crime, strong on welfare," said Charlie Manning, Romney's political consultant.
Manning added, "When you're wrong, you yell and shout, and Ted Kennedy was yelling and shouting."
Although the race is considered Kennedy's toughest in memorey, a weekend poll showed he had an 18-point lead over Romney.
Campaign observers say if Romney wants to narrow the gap, he must deliver a great performance in tomorrow's debate at Holyoke Community College--the last meeting between the two before the Nov. 8 election.
At tomorrow's debate, 12 citizens will ask questions to each candidate.
Outside historic Faneuil Hall, 5,000 supporters of both Kennedy and Romney turned out before the debate, loudly exhorting their respective candidates.
Romney supporters cheered, "Let's Go Mitt," and the Kennedy faithful replied "Go Home Mitt."
A brief skirmish even broke out between the candidates' supporters after the debate