Prince George's and Hagerstown scored in the final seconds to advance in the second day of the Maryland junior college basketball tournament at Montgomery-Takoma Park yesterday. Essex put all five of its starters in double figures to defeat Montgomery-Rockville, 67-58. Chesapeake also advanced.

Steve Mosedale's basket enabled Prince George's to withstand a second-half rally in beating Frederick, 57-55. Ed Fleming scored 16 points and Mosedale had 14 for the Owls (15-6). Bill Miskell led the Cougars (12-9) with 14.

Tim Marshall of Hagerstown stole the ball with two seconds to play and made a layup at the buzzer in a 52-50 victory over Charles County. Doug Huff scored 16 points for Hagerstown (15-11), which trailed at intermission, 30-26. Mike Briscoe led Charles County (10-10) with 18 points.

Tyrone Turner led Essex (16-9) with 18 points and Andre Brown added 14. Harry McCoy scored 13 points for the Knights and Dave Young and Larry Dechter added 12 apiece. Tim Wilson scored 24 points and Ray Wallace 19 as Chesapeake (13-6) won, 69-57, over Garrett (9-15). The Lakers, who led at halftime, 24-22, were led by Kevin Phillips' 18 points.