The Bullets played the entire game without injured guard Frank Johnson and lost forward Greg Ballard early in the first half when his back stiffened, but still had little difficulty in defeating the Chicago Bulls, 110-92, last night before a Capital Centre crowd of 5,622.

It was the Bullets' third straight victory, but they failed to gain any ground on the New York Knicks, who beat New Jersey, 103-92, to remain 2 1/2 games ahead of the Bullets in the race for the sixth and last playoff spot in the Eastern Conference.

Jeff Ruland scored 33 points and Rick Mahorn 22, as the Bullets dominated play inside. Charles Davis, substituting for Ballard, had a career-high 21 points.

Perhaps the biggest lift, however, was provided by former Bull Ricky Sobers. With Johnson sidelined with a jammed big toe on his right foot, Sobers moved over to point guard from his normal shooting guard position. He not only had 13 points, 11 assists and four steals, but made it a long, miserable night for Chicago's Reggie Theus.

Theus went into the game as the NBA's fourth-leading scorer with a 25-point average. Sobers, who was a teammate of Theus in Chicago the last three seasons, held Theus to a season-low seven points and forced him into six turnovers in 33 minutes.

"We got sensational games from Rick Mahorn and Jeff Ruland in the first half, which gave us control of the game," said Bullets Coach Gene Shue, "but I really want to single out Ricky Sobers. He was so ready to play and the great defense he played on Theus was the key. Theus wasn't a factor.

"Ricky really wanted Theus, too," added Shue. "Normally, with Frank not able to play, I would have put Ricky on the point guard and had Don Collins play Theus, but not tonight. Ricky wanted Reggie and I made up my mind early to let him have him."

Sobers said he tried to pressure Theus as much as possible. "I tried to rattle him by putting a little extra pressure on him," he said. "I thought I could force him into some turnovers by pressuring him because he doesn't like that."

Sobers was signed by the Bullets as a free agent, after the Bulls failed to offer him a contract this season.

The Bulls scored the game's first six points, but after Shue called a timeout and let his players know what he thought of their lackadaisical start, they came out and played well.

After trailing, 15-8, they outscored Chicago, 21-6, the remainder of the first period and were never slowed.

Ruland scored 21 of his points in the first half and Mahorn 14, including 10 in the second quarter, as the Bullets led, 59-43, at halftime.

Carlos Terry, who had seven rebounds, five points and three assists in 20 minutes, said, "It got down to banging, and that's our game. With Ruland and Mahorn, that's a thousand pounds coming down on you and that wears you down."

Ruland made 15 of 20 shots, most of them layups, and Mahorn added 10 rebounds and didn't commit a turnover in 41 minutes.

The Bullets had only 17 turnovers, costing them 11 points, while the Bulls turned the ball over 22 times, resulting in 30 Washington points.

The Bulls staged a couple of brief rallies, but never got closer than 12 points in the second half. Davis, who had 19 points in his previous game, had 12 of his points in the third quarter. "I'm just in a groove, now," he said. "I'm relaxed and not rushing my shot."

Chicago, led by former Bullet Dave Corzine's 22 points, had a two-game winning streak broken.

The Bulls had plenty of local flavor with Corzine, former Paint Branch High School player Tracy Jackson, former Howard star Larry Spriggs and Quintin Dailey, former Cardinal Gibbons of Baltimore guard, all on their roster.

Earlier in the day, the Bullets signed rookie free agent forward Joe Kopicki, to take Spencer Haywood's place on the roster. Haywood retired Monday. Kopicki was drafted by Atlanta and was playing in the Continental Basketball Association for Wisconsin when the Bullets signed him.