For Parkville, Wednesday night's game was a matter of survival. The Knights had to overcome miscues and dodge a few gritty comebacks from Dulaney before prevailing, 58-55.
Parkville (10-6) looked comfortably ahead, 51-40, with about five minutes remaining when the Lions went on an 8-1 to cut the lead to three points.
Dulaney also whittled the margin to two points twice in the final minute.
"It was one of our more gustiest wins of the year," Knights' coach Chris Panos said. "We had a nice lead, gave it up a little bit and fought hard to keep it."
Senior forward Skylar Collins led the winners with 26 points and teammate Martaz McKenzie added 10.
Dulaney had four players score in double figures: Will Darley (19 points), Jordan Williams (13), Gavan Scanlan (11) and Chris Conway (10).
Parkville took its first lead, 30-28, midway through the third quarter since the opening seconds on a Collins layup.
The Knights led 37-36 after three quarters, but opened the final period on a 13-4 run to pull ahead 50-40 with 5:17 left as Sterling Myles scored four points in that span.
Dulaney (9-8) used an 8-1 run to make it 51-48 with 2:20 remaining and twice in the final 20 seconds, the Lions trimmed the margin to two points
Parkville held a 58-55 advantage with 4.3 seconds to go when Collins sank a free throw.
Dulaney had one last chance for the game-tying shot, but Darley's three-pointer went off the front of the rim.
"Will is one of the better shooters in the area," Dulaney coach Matt Lochte said of a player who averages 26 points per game. "There's no question about it. He has 15 (Division II, III) schools looking at him. For us to have a look with four seconds left, having to go full court and us down three, there is definitely still a chance."