Spezza scored shorthanded 2:48 into the second period, slipping past Vrbata and flipping a shot over Smith's shoulder to put Dallas up 1-0.
"We don't play too bad, but we end up losing another one-goal game. It's not good enough," Vrbata said. "We have to find ways to win those close games. The special teams make the difference. The shorthanded goal was on me, and they get a power-play goal, and that's the difference."
Duclair scored his second goal of the season to tie it 1-1 at 3:37 of the second. Lehtonen made the save on Martin Hanzal's shot, but the puck sat in the crease. Tobias Rieder took two swings at it before Duclair finally pushed it over the goal line.
Duclair, who scored 20 goals last season as a rookie, had not scored since Nov. 3 against the Nashville Predators.
"It's been awhile … way too long. For that puck to go in was a pretty good feeling," Duclair said.
Benn scored his 10th goal, sixth on the power play, at 12:03 of the second to make it 2-1. Tyler Seguin's pass missed Benn's stick but deflected off his skate and behind Smith, who appeared to kick the puck into his net.