The victory gave the Tigers the conference's automatic bid into the NCAA tournament.
The Nittany Lions (12-4) outscored Towson 4-3 in the fourth quarter as it tried to rally from an 8-6 deficit. The game was tightly contested until late in the second quarter and into the third, when the Tigers (10-7) went on a 5-0 run.
Towson was making its first appearance in a CAA final since 2010, when the Tigers fell to Delaware, 12-9.
Johns Hopkins 9, Army 4: The Blue Jays (9-5) used tough defense to stop the host Black Knights (8-6) from scoring in the first and third quarters.
Brandon Benn scored three of his game-high four goals during a 3-0 run to break the final tie, 3-all. The run started with 3:27 left in the first half and ended with 5:47 left in the third quarter.
Benn started the final 3-0 run in the fourth quarter and Ryan Brown (three goals) scored twice.
No. 12 Princeton 14, No. 2 Cornell 13, OT: Mike McDonald scored a game-high seven goals, but his second assist to Kip Orban, who scored the game-winner with 1:19 left in overtime, helped send the visiting Tigers (9-5) to Sunday's Ivy League championship.
The Big Red (12-3) took a 4-3 lead after the first quarter. Every quarter that followed ended in a tie: 6-all, 7-all and 13-all.
McDonald's seventh goal gave Princeton a 13-12 lead with 2:37 left in the game, but Steve Mock tied the score with 1:41 left to force overtime.
No. 14 Yale 9, No. 17 Penn 6: The host Bulldogs (10-4) outscored the Quakers (8-5) 4-1 in the fourth quarter to win an Ivy League semifinal in Ithaca, N.Y.
Trailing 3-0 after the first quarter, Yale battled back to advance to the tournament final for the second year in a row. Yale faces No. 12 Princeton in Sunday's championship at 11 a.m.
Detroit 7, Marist 6: Mike Birney broke the third and final tie by completing his fourth hat trick of the season with 1:25 left in the game as the Titans (4-9) upset the top-seeded Red Foxes (10-4) in a Metro Atlantic Athletic Conference semifinal at Canisius in Buffalo, N.Y.
A.J. Levell made 17 saves for Detroit, which advanced to the title game for the second time in school history.
Siena 11, Jacksonville 8: Clive Collin had four points (two goals, two assists) to lead the Saints (8-8) past the Dolphins (8-5) in a MAAC semifinal at Canisius.
Siena faces Detroit in Sunday's championship at 1 p.m.
No. 7 Stony Brook 18, Vermont 4: Demmianne Cook became the Seawolves' all-time leading goal scorer on an assist from fellow Adelphi transfer Claire Petersen as host Stony Brook reached its second straight America East conference title game, where it will face Albany, a 13-6 winner over New Hampshire, on Sunday at noon.
Cook scored seven goals for Stony Brook (15-2, 6-0), an America East Championship record, and has 151 for her career despite playing only two seasons with the Seawolves.
Florida advances to the final for a second straight year to face No. 4 Northwestern on Sunday at noon.
No. 4 Northwestern 9, No. 8 Penn State 8, OT: Amanda Macalusu scored the game-winner, her 23rd of the year, with 3:45 left in overtime to lift the Wildcats (16-2) over the Nittany Lions (12-6) in an ALC semifinal at Johns Hopkins.
Jenna Mosketti (Fallston) scored two of the final three goals by Penn State to tie the score at 8 and force overtime.
No. 19 Dartmouth 11, No. 12 Princeton 10, 2OT: Hana Bowers scored the tying goal with 5:11 left in regulation and the winner with 1:22 left in the second overtime as the Big Green (10-6) outlasted the Tigers (10-6) in an Ivy League semifinal at Penn.
Dartmouth advances to face top-seeded host No. 17 Penn on Sunday at noon.
No. 17 Penn 10, Cornell 5: Meredith Cain scored two of her three goals in the first half to lead the host Quakers (10-5) past the Big Red (10-6) in an Ivy League semifinal.
Penn led 6-4 at the break.