Sidney Lowe tipped in a missed shot with two seconds remaining in overtime, lifting fourth-ranked De Matha to a 71-69 victory over Overbrook of Philadelphia in the first game of the Super Sunday Slam Dunk Showdown Doubleheader today at the Civic Center.

In the feature contest Gene (Tinkerbell) Banks scored 25 points and collected 14 rebounds, igniting West Philadelphia to a racehorse victory over Dunbar of Baltimore, 80-65, before 9,322 at the Civic Center.

De matha led, 39-28, at intermission but Lewis Lloyd and Carleton Willis send the Panthers ahead, 50-48, after three periods.

The score seesawed in the next eight minutes with Charles branch keeping De Matha in the game and Willis doing the most of the damge for the Panthers.

Branch, who scored 10 of his 13 points in the fourth quarter, converted a three-point play with 1:22 in regulation to tie the game, 65-65.

Willis tipped in a basket to temporarily put Overbrook ahead before Branch sank a short jumper with 56 seconds left to send the game into the extra session.

Both teams scored a basket in the first minute of overtime. Branch drew a charge and set up a last shot by De Matha Paul DeVito missed from 15-feet but Lowe sneaked in underneath taller Overbrook players and provided the winning basket.

Both West Philadelphia (23-0) regarded as the No. 1 team in the nation, and Dunbar, 23-1, ran, rebounded and dunked with abandon.

Although Banks clearly demonstrated countless basketball skills that have made him the most recruited Philadelphia prospect since Overbrook's Wilt Chamberlain, De Matha's Derek Whittenburg stole the hearts of the fans. The 6-0 sophomore outdueled Banks. Fort Hamilton's Albert King and area players, Justin Ellis of St. John's, Eric Dozier of Carroll. Gerald Watson of Mackin and teammate Clarence DesBordes to win the slam dunk contest.

Whittenburg was perfect on four dunks, on one he made a 360-degrce revolution before slamming it through.