All three Harvard competitors advanced to the finals in the NCAA fencing championships after the first day of action in Chicago yesterday.

Moving into today's second phase of action, each Crimson fencer had moved up in tournament seedings. Geza Tatrallyay, seeded fourth in his pool at the outset of the epee competition, stormed into the lead by the end of the day. Tatrallyay, exuding a quiet confidence, convincingly destroyed all his opening day opponents.

Terry Valenzuela, Harvard's top sabre man, moved up to fifth from and initial seventy-place seeding in his pool. In an important and emotional contest, Valenzuela trounced Navy's Terry Rose to avenge a heart-breaking defeat at Rose's hands that had knocked Valences out of the finals at the Eastern championships. In the Easterns, Rose had tied Valenzuela in the last bout of the day, before defeating him in a fence-off.

The Crimson's foil representative, Don Valentine, also advanced to fifth, up three spots form an initial eighth-place needing. Valentine started very strongly but ran into difficulty late in the day's action, dropping four bouts in a row.

With the competition quickly drawing to a close. Valentine was faced with the stark possibility of being eliminated from the finals. At this point coach Marion took him aside to calm him down and to set him back on the right track.

"He had worked himself into a crisis," Marion said last night. "I practically had to push him into the finals with the point of my shoe."

Under the ground rules of the NCAAs, two-thirds of the contestants advance to the finals. On each day the field narrows as more fencers are selectively eliminated. The tournament culminates on Saturday with the crowning of the team and individual champions and with the naming of this year's All-American team.

Marion, while encouraged by Harvard's first-day performance, would not let himself be drawn into unjudicious predictions for the Crimson.

"This tournament is to long and demanding that the first day means nothing." Marion said yesterday. "The third day will show who has lost stamina and who hasn't. Those that survive are the true champions."