The man in the plaid shirt was reportedly a daily customer at the Clarendon Little Tavern in Arlington, but instead of leaving after he finished his hamburger late Thursday afternoon, he allegedly tried to rob the place.

Thus began the Catsup Caper.

What the would-be robber hadn't counted on was tangling with cook-waiter-cleaner Stephen G. Seman II, who wields a mean squirt bottle of Hunt's Tomato Catsup. He let the guy have it right in the puss, foiling the alleged robbery attempt and becoming a Little Tavern hero in one fell squirt. Police have charged George Taylor, 37, of the 1100 block of North Danville Street in Arlington with attempted robbery in the incident.

As the 19-year-old Seman recalled the events yesterday, a man walked into the restaurant at 3125 Wilson Boulevard about 4:20 p.m. "He sits up on the stool and eats his hamburger," Seman said. "But instead of leaving like he usually does, he said he had a .32 pistol in his waistband and said for me to open the cash register."

That's when the alert Seman, employed at the Little Tavern for four weeks, reached for a squirt bottle of catsup stashed beneath the counter out of the man's sight. "I figured he'd think I was going to the cash register, but I pulled it out and squirted it in his face," Seman said. "I figured I'd blind him first."

After a well-aimed squeeze to the face, said Seman and Arlington police, Seman vaulted the counter and knocked the man to the floor, hitting him when he struggled and cutting his own hand, which required stitches. As they wrestled, Seman hollered for a customer to call police and pinned the man until police arrived a few minutes later.

Police discovered the man had no gun.

"After I had him on the floor," Seman said, "the first thing he said was the reason he did it was because he had a wife and four kids and he was hungry. But when I told him that was no reason to rob and that he could get a job, he said he knew he was going to get caught and needed a place to stay for the night."

Taylor was being held on $25,000 bond in the Arlington County Jail, where, incidentally, inmates yesterday were served lunch that included french fries and catsup.