The two mayoral candidates this week offered a preview of the closing weeks of the campaign as incumbent Thomas Menino defended a record of lower crime during his tenure and a history of fighting foreclosures, while City Councilor At-Large Michael Flaherty hammered the mayor over underperforming schools in the system and City Hall’s e-mail deletion controversy.

But both candidates came across as careful Monday night on the stage of the John F. Kennedy Library and political observers in City Hall and on Beacon Hill agreed Menino held his ground as Flaherty, seeking to close the gap between him and Menino in the polls, performed well but didn’t land a knock-down blow.

“At this point, you’re trying to be so cautious,” said John Tobin, district city councillor for West Roxbury. “It’s a sound bite world we live in. You trip up and it’s repeated over and over again.”

State Rep. Brian Wallace,a Flaherty supporter and a South Boston Democrat whose district includes a part of Dorchester, said Flaherty appeared “pretty mayoral. I thought he acquitted himself quite well. There was no knock-out punch, obviously. [Menino] did what he had to do.”

Tobin, who is unaffiliated in the race, said Flaherty’s criticism of the state of the city’s schools – 100 out of 143 schools have been deemed underperforming – will likely be the at-large city councillor’s theme in the next week or so as they barrel towards the finish line.

“I’ll give you an F,” Flaherty said after asking Menino to look at the camera and grade himself. Menino said the city’s school drop-out rate has decreased during his tenure, but added there was room for improvement. “I’ll give myself a B,” he said.

Flaherty also hit Menino over the e-mail deletion controversy roiling City Hall, saying the administration was involved in the “wholesale destruction of public documents” amid an ongoing federal investigation into former state Sen. Dianne Wilkerson.

Menino said his administration had been cooperative over the e-mails. “We haven’t been charged with anything,” Menino said, dismissing Flaherty’s comments as election year politics. “I think my administration has been as open as any administration in City Hall,” Menino added. “We put them online so the public could see what the e-mails were about.”

Menino, who has been in the mayor’s office since 1993, said residents preferred to hear about issues like housing and crime, and pointed to his administration’s work in stabilizing foreclosed properties on Hendry St., a four-block area that at one time had as many as 16 troubled properties.

Flaherty, who has served on the council since 1999, said he would push for increased financial literacy and help prevent predatory lending through education programs in schools.

On the topic of crime, Menino said there had been a decrease in the murder rate and the number of shootings. Flaherty shot back that 1,000 murders occurred during Menino’s tenure. “Crime stats… don’t tell the whole story,” Flaherty said.

Asked to recall their biggest mistakes, Menino said his was not being able to convince the Legislature to provide more aid to the city. “Mine would be that I didn’t run four years ago,” Flaherty quipped.

Unmentioned in the debate was the vote of “no confidence” that a group representing minority police officers publicized hours before the debate. And Flaherty only twice mentioned City Councillor At-Large Sam Yoon, who finished third in the Sept. 22 preliminary behind Flaherty, whose bloc of votes Flaherty is counting on to help beat Menino and who has been promised a deputy mayorship should Flaherty win.

The hour-long forum was sponsored the Boston Globe, New England Cable News, WGBH-TV, and WBUR-FM radio. It was moderated by NECN anchor R.D. Sahl and WGBH’s Greater Boston host, Emily Rooney.

The next high-profile face-off between the two candidates is scheduled for Tuesday, Oct. 27 at Faneuil Hall. The forum, sponsored by MassVOTE and dozens of other local organizations and newspapers, starts at 6:30 p.m.

Hundreds of Menino supporters held signs down the road from the JFK Library and appeared to outnumber Flaherty backers who mostly stayed near the doors of the presidential library and museum.

After throwing chants and taunts at one another, each side retired to their own watch parties. Menino supporters headed to the Mount Vernon St. offices of SEIU 1199 United Health Care Workers East while a number of Flaherty backers viewed the debate at the Banshee restaurant on Dorchester Ave.