His fourth-ranked Overlea Falcons led 2-1 at halftime when coach Doug Eisenhauer told defender Ron Phillips to tightly mark Dulaney's Matt Rich.
Eight minutes into the second half, Rich, a second-team All-County midfielder, justified Eisenhauer's concern.
The senior assisted on goals by Booth Farwell and Mike Mainquist as No. 13 Dulaney (5-0) edged Overlea, 3-2, in a non-league battle of unbeaten Baltimore County teams.
The Falcons (6-1) entered the game having outscored their opponents 17-4 with three shutouts -- including a season-opening 2-0 victory over No. 12 C. Milton Wright -- and had contained Rich at his center midfield position in the first half.
But a second-half adjustment by coach Craig Laferty freed Rich on the wings and shut down the Falcons' second-leading scorer Rob Ennis (five goals, two assists).
"I pulled Matt outside and put [junior defender Darren] Seibert on Ennis," said Laferty, whose Lions were 4A regional champs last year.
His strategy paid off six minutes into the half.
Rich raced to the penalty area's high right corner and fired a cross to Farwell at the left of second-team All-County keeper Lance Burgess (10 saves). Burgess had little reaction time before Farwell one-touched the ball past him.
Two minutes later, Rich juked Phillips, served a similar pass to Mainquist at the left post, and Mainquist scored his fourth goal of the season -- and second of the game.
"I'm predominantly left-footed. Their coach knew it and he told them to take away my shots on that side," said Rich, who has a goal and five assists. "So on the first goal, I faked to my left and had all the time in the world to cross it to my right. The second one, I just pushed past him [Phillips] and saw Mike there."
But the Lions, who trailed 18-17 in shots on goal, needed a clutch effort by 6-foot-3 goalkeeper Alex Collier (11 saves) to survive.
With six minutes left, Collier blocked a penalty kick by Overlea's scoring leader, Jason Owens (six goals, three assists), leaping to his right for a double-handed swat.
"I was reading his feet," said Collier, a transfer from Virginia. "He looked at the corner and faced his body the same way."
Dulaney had outscored its first four opponents 16-1, with three shutouts, behind Collier, second-team All-County stopper Dan Zakai (6-1) and sweeper Dan Sherwood (6-3).
The Lions took a 1-0 lead at 2:35 into the game after Mainquist chipped in a rebound of an Eddie Liu shot that bounced off the right goal post. But Owens retaliated seven minutes later with the tying goal, stealing a pass from defender Brian Frank and burning Collier on a one-on-one opportunity.
Overlea's Buddy Prochazka made it 2-1 with 12:39 gone after Donnie Long headed down a corner kick by Ennis. The ball dropped at Prochazka's feet, and the junior defender lofted a 15-yarder over Collier's outstretched hands.
"Today, they wore our guys down with their depth. We only have four seniors, but played our best of the year," said Eisenhauer, whose Falcons were regional finalists last year.