IF YOU'VE been following the mayor's race closely, you know that little moments of levity have been as precious and rare as a pond in a desert.

Thanks to a glut of forums and meet 'n' greets, the six Democratic mayoral candidates have probably spent more time together, reciting their pitches, than you've spent fiddling on your phone.

But when the gang got together again yesterday at St. Joseph's University for a second official debate, the audience was unexpectedly left in stitches on a few occasions.

When Fox 29 anchor Lucy Noland asked the candidates a straight yes-or-no question about legalizing marijuana in Philadelphia, former Common Pleas Judge Nelson Diaz blurted: "Yes. I want some."

Former state Sen. T. Milton Street Sr. elicited chuckles when the candidates were asked how they'd handle the city's litter problems.

Street said he would hire community residents to solve the city's trash woes. "We'll clean out lots, and get rid of rats, raccoons . . . [and] kangaroos!"

All were asked whether Eagles coach Chip Kelly is a madman or a mad genius. Street muttered: "Goofy."

But there were plenty of serious - and contentious - moments, too.

Street jabbed at state Sen. Anthony Hardy Williams over a West Philly charter school that Williams founded more than a decade ago.

Street said Williams couldn't "manage" the school, which initially struggled, and thus couldn't fix the city's various fiscal woes. Williams snapped back.

All of the candidates seemed to agree on the importance of improving relationships between cops and civilians, and on the need for an independent board to review police-involved shootings.

Diaz seized that moment to bring up tough-on-crime comments made by former Councilman Jim Kenney to the Inquirer in 1997, including one suggesting that a murderer's hand should have been chopped off.

Williams also took aim at Kenney, criticizing him for voting more than 20 years ago against a City Council bill to ban assault rifles.

A poll of 587 Democratic voters released yesterday by the American Federation of State, County and Municipal Employees showed that Kenney had a razor-thin lead over Williams - 26 percent to 25 percent, with 22 percent supporting former District Attorney Lynne Abraham.

Abraham, who had fainted at the start of the first televised debate earlier this month, again emphasized her toughness and intention to improve the city by sheer force of will.

Beyond the occasionally biting banter, candidates touched on familiar points. Former PGW spokesman Doug Oliver, 40, pitched himself to the St. Joe's students as a breath of fresh air, noting that he was sharing the stage with five people who collectively had more than 100 years' worth of elected experience.

Kenney, Williams and Diaz each assured the students that they knew how things worked in local government, and thus knew how to get things done.

On Twitter: @dgambacorta