"The weekend was very busy," Ruiz said.
He said he served about 400 people on Friday, 300 on Saturday and 200 Sunday night.
On Friday, Ruiz said he had stockpiled 1,000 handmade tortillas in anticipation of the crowds.
"We just blew through those," he said. "Saturday was the same deal."
The restaurant, at 1406 W. Morse Ave., was at capacity Saturday evening for several hours, with long waits to get a table.
Many people ordered the restaurant's famed $6 No Bulls--- Special, consisting of a taco, a shot of whiskey and a tallboy of Pabst Blue Ribbon.
Although Ruiz said the opening weekend exceeded all expectations, the real test would be whether his cantina can stay busy on weekdays.
The original Bullhead Cantina opened in 2012 in Humboldt Park.
Rogers Park's Bullhead will be open from 4 p.m. to 2 a.m. Tuesdays to Thursdays; noon-2 a.m. Fridays; Saturdays noon-3 a.m.; and noon-midnight on Sundays.