In the first game, the Falcons (5-1) saw starting pitcher Kyle Murray strike out nine in a complete-game effort to net a 4-1 win.
Mulcahey, a junior right-hander who played center field in the first game, wanted to keep the Falcons' momentum going after Murray's splendid outing.
"I knew that I wanted to go out there and throw strikes and our defense is a lot better," said Mulcahey, who improved to 2-1 after striking out six. "I got out of a jam [in the first inning] by getting outs on grounders.
"In the first game, I watched what Kyle did to their hitters I studied each hitter and learned what kind of pitches to throw to them."
The Falcons, who stretched their winning streak to five, scored four runs in the bottom of the first against the Wildcats (3-3-1). Mulcahey gave the Falcons a 1-0 lead with a run-scoring single that plated Cole Currie. A wild pitch made it 2-0 before Kyle Pomeroy sliced a two-run single to right to extend the lead to 4-0.
The Wildcats couldn't catch up to Mulcahey, who recorded two strikeouts in the first and second and one more in the third. Mulcahey finished with a team-best three hits, including a two-run home run to left to give Crescenta Valley a 6-0 lead in the fourth.
Crescenta Valley Coach Phil Torres wanted the Falcons to continue their trend of strong starting-pitching performances.
"In all six games we have played, we have pitched real well," Torres said. "[Pitching Coach] Darrin Beer has done a great job with our pitchers.
"They've gotten better command of their fastballs and their secondary pitches."
The Falcons collected eight hits against three Monrovia pitchers.
Crescenta Valley second baseman Andrew Fagundo made a diving stop to his left on a grounder to record the third out and preserve the shutout in the fifth.
Monrovia scored its run in the seventh off reliever Elliot Surrey, who pitched the final two innings.
In the first game, Murray (1-0) scattered five hits. Pomeroy had a sacrifice fly in the first inning to give the Falcons a 1-0 lead.
Pomeroy then hit a solo home run in the sixth inning to cap the scoring.