PROVIDENCE, R.I. April 25--A gaily bedecked and somewhat besotted crowd of spring celebrants invaded Aldrich Dexter field today to watch the Brown lacrosse team rough up "the Crimson weanies."

But, as one official said when a Harvard player complained of a poke in the head, "You Harvard boys are dishing it out too." And so they were, in large, undigestable lumps.

The result was a 7-5 Harvard victory, which gave the Crimson undisputed possession of first place in the Ivy League.

Ted Leary, a sophomore attackman, was the big gun as he scored three goals and assisted on two others. Dick Ames had three assists and Lou Williams a goal and an assist to lead the offense.

Coached by the excitable Cliff Stevenson, Brown lacrosse and soccer teams are reknowed for their bruising style of play. A good deal of extra-legal skull-duggery transpired today, but with such solid citizens as Charlie Kessler and Dan Calderwood in the lineup, Harvard was not pushed around.

The Crimson took a 1-0 lead after two minutes when Tink Gunnoe fired in a rebound from 10 feet out.

Brown tied it up at the start of the second period, but despite several near-misses could not score again. Mike Bassett then scored on a quick stick shot, and Leary converted a pass from Williams to give Harvard a 3-1 halftime lead.

Pete Wood stretched the lead to 4-1 at the start of the second half. But Brown capitalized on two penalties to cut the lead to one goal, and the long- silent Bruin partisans came shrilly to life.

A Brown goal was sandwiched between two sensational scores by Leary, the second coming at 3:16 of the final period. With Harvard ahead by two, Brown's Jerry Zimmer tallied on a long drive at 6:46 to make the score 6-5.

The Bruins then put on the pressure. Goalie Orm Hammond made several spectacular stops, and two shots hit the pipe. Brown kept coming, but Gunnoe deftly stole the ball from Brown's All-American candidate, Tom Draper, to end the threat.

Williams scored Harvard's final goal with a minute to go.

The big game is this Saturday. Victorious in nine straight, Harvard meets Princeton--which has not lost an Ivy game in the seven years the league has been official