Duke Cano had been onstage only twice before he was asked to kill a couple of minutes at Comedy Corner Underground's free open mic last week. At various moments the aspiring comic's fill-in set triggered chuckles, crickets and even a little compassion after a joke belittling the size of his manhood.

"When they came up and told me I was going to be next, my heart was like 'ba-bump, ba-bump,' " he said.

For the past decade the comic-run basement club beneath the Corner Bar in Minneapolis has been a quirky staple in the Twin Cities comedy scene, where everyone from Cano to college students and former local luminary Cy Amundson has logged invaluable stage time. On Friday, the scrappy dungeon of laughs celebrates its 10th anniversary, bringing back comics (some performing their same sets) from its inaugural show.

"For some of us that haven't written any new material that'll be no problem whatsoever," joked founder Marc Dickhut.

Ten years ago Dickhut, who's no longer heavily involved with the club, was a stage-hungry comic with limited open-mic options. Dickhut convinced pal and Corner Bar owner Bill Murray (nope, not that one) to let him convert the bar's basement storage space into a small comedy club.

In the early days, the Comedy Corner Underground was lucky to draw a handful of comics and 25 audience members. Now, up to 60 comedians vie for the 20 time slots and the intimate 65-seat room is packed every Friday, according to current manager Bob Edwards.

Local comedians describe CCU as a safe space where (almost) anything goes. Weekly Thursday shows with alternative themes and formats also help foster an outside-the-box mentality.

"At a [traditional] club, you're trying to do stuff that will impress them so you can get hired a lot of times," said comic Rana May. "That's still a worry here, but there's a little bit more of an experimental, try-something-out vibe. Everyone's open to it and appreciates it here."

The popular Friday open mic can be a roller coaster of teary-eyed laughter and awkward silences. During a rapid-fire comic roulette, jokesters with disparate styles and skill levels hit the makeshift stage for three to five minutes, some with notes scribbled on their hands or "cue cards" on their phones when the next joke is forgotten.

While other comics' prolonged bits on fruit trays and dead relatives bombed, May's deadpanned tale about "reverse street harassment" garnered some of the biggest laughs of the night.

Comedy Corner Underground has become a destination for both first-timers and full-timers. While it's a club designed for locals, such national touring comics as Nick Griffin and Zach Sherwin (Feb. 18) have looked to play the tiny club even though they could fill a bigger room, Edwards said.

As the club's reputation has grown, so has the Twin Cities comedy scene. In 2005, Quash says there were only 30 to 40 comedians in town. Edwards keeps a database of local comics that has swelled to about 500 in the past two years, though some were merely testing the waters.

"It's great that they give people a chance to come and give what they got," Cano said.

And, hey, we'll take the free laughs.

COMEDY CORNER UNDERGROUND 10th Anniversary

When: 8 p.m. Fri.

Where: 1501 Washington Av. S., Mpls.

Admission: $10. 18-plus. 612-492-1197 or www.comedycornerunderground.com.