Siena (4-2) took a 4-3 lead 2:23 into the second half, as Ryan Duggan (three goals) took a pass from Mike Lashomb and scored.
Following a Loyola penalty, Duggan passed to Brendan Murphy, who scored on the extra-man opportunity, giving Siena a 5-3 lead, its largest of the game.
The Greyhounds (3-3) pulled within 5-4 with 8:39 remaining as Taylor Ebsary scored off an assist by Shane Koppens.
Loyola had three shots after that goal in an attempt to tie the game, but Siena goalkeeper Brent Herbst saved all three. Herbst finished with 16 saves in the game.
The Greyhounds forced three Siena turnovers, two on delay calls, in the final two minutes, but Loyola had two turnovers in that span and did not get a shot off after the Saints' final turnover with 18 seconds left on the clock.
Siena struck first, less than three minutes into the game, as Duggan took a pass from Kenny Mazzone and put the Saints ahead 1-0.
Paul Richards evened the score at 1 with 7:36 remaining in the first quarter. A shot by Siena's Shaun Dunn was saved by Loyola goalkeeper Jake Hagelin, and P.T. Ricci picked up the ground ball for the Greyhounds. He fed a clearing pass to Richards, who went nearly coast-to-coast for the unassisted goal.
Catholic 11, Hood 7 -- The visiting Cardinals (3-2) - led by Kyle Brant with four goals - held the Blazers (0-9) scoreless for two quarters. Hood's Jason Anderson had a hat trick.
Mary Washington 7, Goucher 5 -- The host Eagles (4-3) outscored the Gophers 4-1 in the fourth quarter in the win. Goucher led 4-3 going into the final quarter. Casey Hughes of the Gophers (4-2) led all scorers with three goals.
No. 1 Duke 15, Colgate 7 -- Matt Danowski scored four goals and added one assist as the host Blue Devils (8-0) beat the Raiders (4-3). Duke has won 15 straight at home, dating back to last year, and 23 of 25 home games. Less than a minute into the game, Colgate's Nick Monastero scored an extra-man goal to give the Raiders an early lead. Duke responded with five straight goals to end the opening period.
No. 3 North Carolina 12, Marist 3 -- The host Tar Heels (6-1) - led by Bart Wagner with four goals -jumped out to a 4-0 lead after the first quarter. The North Carolina defense held Marist scoreless for three quarters. The Tar Heels outshot the Red Foxes (0-5) 44-34 and scooped up more groundballs, 52-33.
Villa Julie 17, Elizabethtown 14 -- The visiting Mustangs (4-2) took a 9-6 lead at the half before the Blue Jays (2-2) played them even in the second half. Lisa Baker had three goals and assists to power Villa Julie.
Roger Williams 12, Frostburg State 7 -- Claire Halliday led all players with four goals as the visiting Hawks (3-0) ended the Bobcats' three-game winning streak. Elisabeth Hildebrand had three goals for Frostburg State (3-3).