Dartmouth quarterback Steve Case demolished the Harvard J.V. by galloping for three touchdowns and tossing two others as the Big Green rolled over the Crimson 32-6, at Hanover, N.H., yesterday.

The setback extended Dartmouth's unblemished record to four games and dropped the Crimson ledger to 1-1.

Dartmouth wasted little time in jumping off to a 6-0 lead. A Crimson fumble gave the Big Green excellent field position and Case directed a short drive capping it with a 12-yard ramble into the endzone.

Dartmouth again capitalized on a Harvard miscue for its second score. An interception deep in Crimson territory set up another Case touchdown jaunt and the Big Green held a 13-0 halftime margin.

The Crimson backs had difficulty maneuvering on the rain-soaked turf in the first half, so coach Paul McGuire opted for his aerial attack in the final 30 minutes.

Quarterback Steve O'Brien came out throwing, and connected with Steve Saxon consistently, but the Crimson drives continually sputtered and fell short of the goal line.

The powerful Big Green offense, which has averaged 36 points per game, continued its assault in the mud and added two more six-pointers to give Dartmouth a commanding 26-0 lead.

The Crimson finally got on the scoreboard late in the third period as halfback Alfred Marek took a pitch on the option play and plunged into the elusive endzone for the only Harvard tally.

The Big Green onslaught was not totally demoralizing. The J.V.s were undermanned in much of the first half because some players were tardy following late exams. Coach McGuire said, "I was not real upset with the game. The exams hurt but the main thing was to get some experience."