Tulane quarterback Mike McKay completed 26 of 38 passes for 239 yards and two third-quarter touchdowns as the Green Wave upset Maryland, 14-7, in the Louisiana Superdome tonight.

The defeat assures the Terrapins (3-5-1) of their worst season since 1972, when Coach Jerry Claiborne's first Maryland team went 5-5-1. It was the first time Tulane (4-5) had used one quarterback for an entire game this season.

Tulane, which played, and lost, in last year's Hall of Fame Bowl, is not nearly as competitive this season. Coach Vince Gibson, in his second season, lost 24 lettermen from that bowl team and is in desperate need of a quarterback.

The Green Wave played well in early losses to Ole Miss and Clemson, but lost to Southern Mississippi, Rice and Cincinnati. This Tulane team would figure to be no match against past Maryland teams.

But as Gibson said Friday, "Just like us, Maryland has lost a lot of games by making too many mistakes."

Gibson's words turned prophetic. Tulane committed three turnovers and Maryland two in the scoreless first half, and the most valuable players for each offense were the punters. Tulane's Vince Manalla averaged 50 yards on his first three kicks. Maryland's Alan Sadler had punts of 55 and 68 yards.

It looked like the Terrapins would score easily on their first possession. Surprisingly, Maryland started in a pro-set formation instead of its usual I-back formation.

Maryland quarterback Boomer Esiason still somewhat stiff from the jammed neck he suffered last week, passed 15 yards to John Nash, who started at tailback in place of Charlie Wysocki. Two plays later, Wysocki ran nine yards to the Tulane 44. Fullback Joe Brkovich broke four tackles on a 13-yard run up the middle to the 31.

But the movement stopped there. Russell Davis lost four yards on an end reverse and Esiason's 11-yard pass to Nash on third down was short of a first down. Jesse Atkinson' 41-yard field goal attempt was wide left with 13 minutes to play in the first quarter.

What followed for the rest of the half was a series of punts and errors.

On Tulane's second possession, the offensive line went right while quarterback Mike McKay rolled left. The result was a sack by Mike Corvino for Maryland, moving Tulane back to its 18. Manalla, punting from his end zone, saved the Wave with a 47-yarder, one of his shorter kicks.

Maryland could do no better on its next possession, with Wysocki losing four yards on first down. Sadler, whose first collegiate punt last week carried seven yards, kicked 34 yards on his first try tonight, pinning Tulane on its 10.

Gibson, who talked this week of how Maryland had allowed an average of 282 yards passing, ran half-back Marvin Lewis on first and second down for a total of three yards. Manalla, from his end zone again, punted 51 yards to keep the Wave out of immediate trouble.

The Terrapins' ensuing possession ended with Esiason's second-down bomb to an open Russell Davis being intercepted by free safety Tyrone Smith. He returned it 30 yards to the Maryland 42, but Tulane could produce one yard in three downs. Manalla punted 41 yards into the Terrapin end zone.

After another Maryland punt, Tulane moved from its 25 to the Maryland 32 on passes to Lewis, split end Wayne Smith and tight end Rodney Holman. But McKay's second-down pass to Lewis was intercepted by defensive end Howard Eubanks.

Esiason's 24-yard pass to Nash and Brkovich's nine-yard run moved Maryland to the Tulane 35. But Brkovich fumbled on the next play, and cornerback Casey Howard recovered.

Two plays later, McKay fumbled the handoff to Lewis and Terrapin tackle Burnest Brown recovered. Esiason threw two incompletions and was sacked on third down as Maryland stalled again.

Action picked up considerably in the third quarter.Tulane, with dinky passes and four- and five-yard rushing gains, moved to the Maryland 40. McKay's four-yard pass to Lewis turned into a 19-yard gain because of a face-mask infraction called on Maryland.

On third and two from the 12, McKay sneaked two yards for the first down. On the next play, Lewis caught a screen pass from McKay and ran in for the touchdown to give Tulane a 7-0 lead with 10:07 left in the third quarter.

The Terrapins tied the score three minutes later when Esiason, on third and four from his 38, found Davis at the Tulane 30. Davis slipped away from safety Tyrone Smith and outran three more defenders for a 61-yard touchdown play.

Tulane then put together its second straight scoring drive to take a 14-7 lead with 15 seconds left in the third quarter. Beginning at its 33, Tulane moved to the Maryland six on Marvin Lewis' 16-yard run and passes to Nolan Franz, Wayne Smith and Lewis.

McKay passed six yards for the touchdown to fullback Reggie Reginelli, who caught the pass between safety Wayne Wingfield and line-backer Darnell Dailey.

With less than 11 minutes to play, Maryland used a fourth-and-one run by substitute tailback Tim Whittie and a seven-yard run and 19-yard pass reception by Nash to move to the Tulane 24. But from there, Maryland mistakes took over.

An illegal procedure penalty moved the Terrapins back to the 29. Esiason found Nash with a pass at the 23, but end John Tice was called for another procedure penalty on third and six, putting Maryland back to the 28. On third down, Esiason was sacked for a 12-yard loss and Maryland was forced to punt again, with seven minutes remaining.