Tom Wilson, Ethen Frank and Aliaksei Protas each scored for the Capitals (17-9-3), who finished their four-game road trip 3-0-1. Logan Thompson made 35 saves.
"We probably turned too many pucks over in the second and third (periods) and it fed their transition a bit," Washington forward Dylan Strome said. "Overall, take the positives from the road trip and take the point and move on."
Wilson gave the Capitals a 1-0 lead at 9:29 of the first period. Trevor van Riemsdyk's shot from the right boards hit Justin Sourdif in the right face-off circle. He then tapped the loose puck to Wilson, who beat Husso blocker side with a snap shot from the high slot.
Washington rookie forward Ryan Leonard left the game after taking a hit from Ducks defenseman Jacob Trouba at 16:04 of the first period. The play was reviewed for a major, but the only penalty assessed was to Capitals defenseman Jakob Chychrun for roughing.
Washington coach Spencer Carbery did not have an update on Leonard, who was coming off a four-point game in a 7-1 win at the San Jose Sharks on Wednesday.
"I'm proud of 'Lenno'" Wilson said. "Not many kids get up and skate off the ice after a hit like that. He's in there and hanging with the guys. He's such a good kid that it [stinks] to see that, but he'll be back and he's got a long career ahead of him."
Gauthier tied it 1-1 at 18:16, scoring from the slot off a feed from Sennecke from below the goal line 12 seconds after the penalty to Chychrun expired.
"If you manage the puck well against that team and take it down below their goal line and get moving, you generate things," Wilson said. "They're a good transition team and they've got a lot of young skill, and we could have done a little better job keeping the puck out of their hands in transition, but they're going to make plays, they're good players."
Frank put the Capitals back ahead 2-1 at 6:06 of the second period. A clearing attempt by Ducks defenseman Pavel Mintyukov went between his legs directly to Frank in front, where he lifted a shot past Husso's glove.
Johnston tied it 2-2 just 13 seconds later at 16:19 when he tipped in a long-distance shot from Radko Gudas.
"We responded the right way," Johnston said. "We didn't fold up and we didn't feel bad for ourselves because of what happened the other night."