Pat Bertoletti is a lanky kid from Palos Heights with a trucker hat and a funny grin. He doesn't look like anything special. Give him ten minutes, though, and he can put away 18 bratwursts. Or 228 oysters. Or 211/2 grilled cheese sandwiches, which he threw down in front of 4,000 people in Detroit this past August. You don't want to know what he can do with corned beef. Bertoletti is the tenth-ranked competitive eater in the world, and, at 20 years old, his metabolism is still a work in progress.

And I still thought I could take him.

This was based on the ridiculous assumption that I, a food writer who samples as many as 20 dishes in a single evening, would be a natural contender in the International Federation of Competitive Eating, the professional circuit of a fast-growing "sport" with thousands of eaters registered worldwide. "It is the purest sport in the world-ever," says Richard Shea, head of the federation. "It's as fundamental as running and jumping, both activities that are in the Olympics." The sport's best athlete is the 132-pound Takeru Kobayashi, who sent shock waves and heartburn around the globe by polishing off 531/2 hot dogs in 12 minutes, live on ESPN.

I thought I had experience in these things. So I issued a challenge to Bertoletti: him and me, one-on-one with six large cheese pizzas. Whoever ate more (without a "reversal," of course) was the champ. "That sounds like fun," he said. I tried to skew the match in my favor: He wanted Aurelio's, so I ordered Home Run Inn. He was used to ten-minute competitions, so I made it 20. I even had the home field advantage: the imposing Tribune Tower, where I could pack the office conference room with partisan colleagues. I liked my chances.

"I've always been a big eater," Bertoletti said while we were waiting for the pizzas to arrive. In May 2004, his sister suggested he'd be good at competitive eating, so he gave it a shot. In his first competition (pizza) he tied for first with Richard LeFevre, at the time the seventh-ranked eater in the world (LeFevre won in an eat-off). Since then, Bertoletti, a culinary arts student at Kendall College, has traveled the country on weekends taking on the world's biggest eaters and so far has earned $3,500 in prize money. He trains at places like Hot Doug's, the "encased meat emporium," where he recently tried to finish $100 worth of hot dogs. "I asked for two of everything, ate about $85 worth, then gave up," he said. This anecdote shook my confidence in a profound way; it wasn't until six 14-inch pizzas showed up that I realized I was in way over my head.

It took Bertoletti 6 minutes and 48 seconds to finish his first pizza. I was barely halfway done with mine and was already resorting to pathetic measures like putting two slices in my mouth at once. Soon my shirt was untucked and my ears were buzzing. Bertoletti stayed focused; he never seemed to be eating fast, but he also never stopped: a few chews, a few swallows, and then on to the next slice. I could see why Shea had called him an "upstart gurgitator"-every time I looked over, there were more pieces missing from his box. Was he putting them down his pants?

At the 12:06 mark, I finished my first pizza; Bertoletti was seven slices ahead and showing no signs of slowing. By the 15-minute mark I noticed he was stripping the cheese off each slice and eating it separately. I attempted this method, but the cheese felt like bubblegum and my throat was starting to close. Around 17 minutes, I considered quitting-until I saw Bertoletti across the table, still shoveling it in. I gave myself a mental Heimlich and made one last push.

By the time the final gun went off, I was dripping in sweat and my heart was hammering. Bertoletti looked as if he had just returned from a vacation. Someone asked how he felt. "Not too bad," he said, taking a swig from his water jug. (No one bothered to ask how I felt.) After some quick math, we figured out that he'd eaten 29 slices and I'd eaten 20. As my colleagues dug into the leftovers, the conversation steered toward just how easy the kid had gone on me. "I wasn't really in the mood for it today," admitted Bertoletti, who claims to have suffered no adverse effects so far, like weight gain or, perhaps, an enlarged spleen. "Besides, people get grossed out when all-out tactics are used."

"So what's the secret?" I asked. "How do you do it?"

"There's no secret. You just have to learn to eat through the discomfort," he said. "It's the natural ability that I was born with." (I found out later he had also drunk a gallon and a half of water a couple of hours before our competition to help "stretch" his stomach out. I hadn't drunk a thing, which explained why I was dehydrated for days following the competition.)

Bertoletti shook my hand and wandered out of the office mumbling something about an upcoming chicken wing contest in Seattle. After spending the next six excruciating hours alternating between my desk and the bathroom, I had learned my lesson. Next time I felt like having a pizza eating contest, I would resist. Next time, I would not get in over my head.

Next time: cheeseburgers.