Tom Sluby scored 23 of his 32 points in the second half to offset a spectacular 42-point peformance by All-Met Kevin Darmody and give Gonzaga a 69-66 victory over O'Connell last night in the opening round of the Washington Invitation Tournament at O'Connell.

In other opening action, Joedy Gardnerhs 25 points lifted St. John's to a 77-64 victory over Georgetown Prep and Ben Franklin of Philadelphia, trailing, 73-44, forfeited its game to Flint Hill, with 1:40 to play.

In tonight's semifinals Gonzaga takes on Dunbar of Baltimore at 7, followed by Sy. John's against Flint Hill.

Overbrook, rated the nation's No. 1 high school basketball team, was scheduled to meet the winner of the Gonzaga-O'Cnnell game. But the Hilltoppers, who beat De Matha, 61-60, two weeks ago, withdrew from the tournament to play Roman Catholic for the Philadelphia city championship this afternoon.

The Philadelphia chamipionship was to have been held Wednesday night. Because of problems with unruly spectators at the Palestra in the public school final between Overbrook and Ben Franklin, Palestra officials would not allow the city championship to be played there.

John Meyer of Gonzaga hit four free throws in the final 20 seconds to negate two foul shots by Bob Zillian.

Sluby, a second-team All-Met forward who came into the game averaging 22.7, scored 14 points in the third period, hitting all seven jumpers, to put Gonzaga up, 50-42, at the end of the quarter.

Then it was Darmody's turn once again to show off his beautiful flowing jump shot from all points on the court. Darmody, who will attend South Carolina next year, scored 17 points before Fouling out with 31 seconds to go and his team trailing, 65-64.

Gardner and Jim Devaney contributed 24 points as St. John's (17-9) raced ahead, 40-25, at intermission.

St. John's shot poorly in the third period and with 5:33 remaining, Prep moved to within 54-47. That rally woke up the 6-foot-3 Billy Freitag, whose 11 points from there on in kept St. John's on top.

Flint Hill (21-6) outscored Franklin, which replaced Overbrook in the tournament, 17-7 in the third period to take a 46-34 advantage as the Electrons forced shots against their taller Flint Hill opponents and connected on only one of 14 field-goal attempts in the quarter.

Flint Hill coasted through the last period, marred by two technicals against Franklin Coach Ken Hamilton, who was frustrated with the officiating and his team's inability to put the ball though the hoop. Another technical was slapped on Franklin's Lonnie Jackson, who was ejected for shoving Flint Hill's Danny Copeland.

With 1:40 to go and his team losing, 73-44, Hamilton called to his squad, "Hey, team, let's go," and forfeited the game.