Navy's first appearance in the NCAA baseball playoffs in the last 25 years ended abruptly today. The Mids were eliminated by opportunistic Nebraska, 13-4, at Bishop Field.

In another game, St John's, the tourney's only unbeaten team, defeated Connecticut, 6-3. Connecticut plays Nebraska at 1 p.m. Sunday with the winner meeting the Redmen at 3:30.

The Mids, who lost to Connecticut, 5-4, in a rain-shortened contest Thursday, never were in today's game. They fell behind, 6-0, after two innings and became the first team to be oustead in the Northeast Regional double-elimination tournament.

"In a game like this against top-flight competition, you can't handicap yourself by getting six runs behind," Navy Coach Joe Duff said. "That was the ball game."

Duff elected to start senior pitcher Rocky Kropp, who came into today's game with a 6-0 mark and a 1.84 ERA. But Nebraska (49-14), handcuffed on three hits in losing its first game to St. John's, 5-0 earlier today, took out its first-game frustrations on the shaky Kropp.

"We just got the kinks out and didn't play well aginst St. John's," said Nebraska center fielder Joe Scherger, who drove in four runs against Navy. "Our bats were the problem the first game but not the second one."

A run-producing single by Scherger, hitting .333 coming into today's action gave the Cornhuskers a 1-0 lead after one inning.

Kropp struggled that inning, throwing 21 pitches, but managed to get out without any more damage. In the second inning he was not so fortunate.

Kropp got Nebraska's leading batter, first baseman Pete O'Brien, to fly to center but then lost sight of the plate. The left-hander walked Steve Oakley, then yielded singles ot Greg Shafer and Stan Haas. Oakley had stopped at third but scampered home when Kropp let the relay throw get past him.

Seconds, later, Kropp threw a wild pitch that allowed Schafer to score and put Nebraska ahead, 3-0.

That was it for Kropp. His replacement, Senior Steve Walton, was even worse. He gave up an RBI single to Bob Gebler and two more walks before departing.