Chuck Fusina passed for 310 yards and Mike Lush returned an interception 56 yards for a touchdown to lead the Baltimore Stars to a 27-14 upset of the Houston Gamblers in a U.S. Football League game today.

Alan Harvin, filling in for injured running back Kelvin Bryant, rushed for 113 yards, but it was the Stars' defense, forcing five turnovers, that produced the Gamblers' first regular-season loss since May 6, 1984, at Michigan.

The Stars improved their record to 2-3-1. Houston fell to 5-1.

Houston's Jim Kelly, the league's leading passer, completed 33 of 51 passes for 393 yards and two touchdowns, but threw three interceptions. "He's the class of the league," said Lush. "We just tried to keep them from making the big play on us." Of the interception he returned for a touchdown, Lush said, "I was just laying back in a zone and Kelly overthrew his receiver. The rest was just luck."

Fusina put the game in perspective. "This was not a battle between Kelly and myself. I have to worry about myself and my team and he has to worry about his."

Gamblers' Coach Jack Pardee was quick to credit the Stars. "They showed us today why they're the defending champs. You just can't give a team like the Stars that many opportunities. We had our chances, we just didn't capitalize on them."

Kelly led Houston 80 yards in nine plays on the Gamblers' first possession, throwing a screen pass to Sam Harrell on first and goal from the five. The Stars were in an all-out blitz and Harrell eased into the end zone.

The Stars cut the margin to 7-3 the next time they had the ball. On the first play following the kickoff, Fusina lofted a pass over the outstretched arm of Luther Bradley to Ken Dunek for a 39-yard gain. A 16-yard pass to Scott Fitzkee gave the Stars a first down at the Houston 12, but two incomplete passes forced the Stars to settle for 27-yard field goal by David Trout.

Houston moved the ball 63 yards to the 10-yard line, but Gerald McNeil fumbled after being hit by Scott Woerner and Lush at the three, and Baltimore's Garcia Lane scooped up the loose ball and returned it to the 10.

Fusina engineered a drive into Houston territory and hit Willie Collier with a 30-yard pass for an apparent touchdown, but the play was nullified by an illegal formation penalty. However, six plays later, Harvin went in on a three-yard sweep around left end.

Baltimore drove to the Houston nine-yard line late in the half but Trout missed a 26-yard field goal attempt.

Clarence Verdin returned the second-half kickoff 28 yards to the Gamblers' 41-yard line. On second and one, Kelly lofted a 50-yard pass to McNeil, who had beaten Lane on a post pattern, to give Houston a 14-10 lead.

Houston regained possession after a fake field goal attempt backfired at its 29-yard line. Kelly's deep pass over the middle was intercepted by Lush at the Stars' 44. Lush spun out of McNeil's tackle at midfield, cut back across the field and scored standing with 4:07 remaining in the third quarter to give the Stars a 17-14 lead they would never relinquish.

Houston drove to Baltimore's 10-yard line following the kickoff but William Fuller sacked Kelly, jarring the ball loose. Fuller recovered to give the Stars possession at their 21-yard line.

Fusina directed a seven-play, 79-yard drive that culminated with a 36-yard touchdown pass to Collier up the right sideline. Collier caught the ball on the four, eluded Mike Mitchell and highstepped it into the end zone to give the Stars a 24-14 lead.

Trout added a 38-yard field goal with 2:26 remaining in the game to close out the scoring.