Temple's coach could only watch as Jerrelle Benimon scored 21 of his career-high 32 points in the second half.
"Obviously, Benimon is a handful," Dunphy said. "I think he's got a really good chance to be in the [NBA] next year."
After Dalton Pepper hit a three-pointer with 9 minutes, 18 seconds to play to give the Owls a 56-49 lead, things went awry.
"We're just not tough enough yet. We're gaining on that," Dunphy said. "I'm not overly disappointed. I'm encouraged where we find ourselves. Now, the disappointment jumps in with holding that lead."
Temple went more than eight minutes without a field goal as Towson (3-0), which received its first-ever Associated Press Top 25 vote this week, took a 68-62 lead with 1:24 to play.
Benimon's two free throws with 13.1 seconds to play sealed the win.
Anthony Lee had 20 poings for the Owls and Wil Cummings had 18.
Benimon, the nation's leading returning rebounder, had 31 in his first two games. He had only 10 against Temple, but the Owls were still outrebounded, 47-37.
"Everything was going through him," Lee said. "You just kind of have to be prepared for what he's trying to do."
Cummings explained the second straight loss. "We've got to learn to put teams away," he said.