Duch scored three goals, including the winner, and also had four assists as Washington beat the Roughnecks 12-11 in the National Lacrosse League, ending Calgary's three-game winning streak.
The win moves Washington into a three-way tie for first place in the West with Calgary and Edmonton, who lost to Colorado on Saturday. All three teams are 8-6 and have two games remaining.
"Their team is so good at getting in shooting lanes. In the first half, I was super frustrated, I was hitting a lot of their players with shots. It was because my feet were set when I was shooting," Duch said. "On that shot, I started moving my feet, which causes the goalie to have to move with you and then you create a better shooting lane for yourself. I drew Poulin to the right and I put it back the opposite way."
Washington scored five unanswered goals to take a 10-9 lead after three quarters, only to see it disappear early in the fourth on goals 10 seconds apart by Jeff Shattler, with his second, and Curtis Dickson, with his third.
Last week in Washington, it was goals 17 seconds apart by Calgary that ignited a seven-goal fourth quarter for the Roughnecks who won 13-11.
The scenario played out differently on Saturday.
Dean Hill tied it for Washington at 11:15 of the fourth quarter and Duch put a long shot past goaltender Mike Poulin a minute later to put the Stealth into the lead.
Key for Washington in that final quarter was stemming the tide after the two quick goals, something they were unable to do a week ago.
"Our defence took a step back and said O.K., what do we need to do to get the offence going," said Stealth captain Kyle Sorensen. "The offence picked us up and put the ball in the net and we ended up gutting it out. It's a character win, it's a gut-check win and it's one we needed because we're moving towards the playoffs now. We've got to be better and there's not much room for mistakes anymore."
Lewis Ratcliff also had three goals for Washington (8-6). Jeff Moleski had a pair while Kyle Buchanan, Mike Grimes and Brett Bucktooth also scored.
Also scoring for Calgary was Dane Dobbie with two goals. Adding singles were Dan MacRae, Geoff Snider, Shawn Evans and Scott Ranger.
Goaltender Tyler Richards preserved the win with some great stops in the late going. Two of his 48 stops were dangerous chances late from Dickson and Evans.
"T-Rich is the backbone of our team and we don't win that game without him," said Duch.
Dickson's second goal of the night at 2:54 of the third quarter had helped Calgary open up its biggest lead of the night at 9-5. However, the four-goal margin lasted just 27 seconds.
Ratcliff's power-play goal was the first of five unanswered goals for Washington who stormed back to take a 10-9 lead to the final quarter.
"We battled but that's not playoff lacrosse, you have to play squeaky clean," said Snider. "There were lots of mistakes out there but just a couple of stupid errors and that's been our challenge all year. We have to be smarter, we have to be more disciplined."
The goal that gave Washington the lead headed to the final quarter came on a power play with Evans sent off for an attempted head-butt in a skirmish with Sorensen. The two long-time buddies are the same age, both are from Peterborough, Ont., and have played lacrosse together since they were kids.
"I noticed that he was fired up, he had been slashed, and you could see it in his eyes that he was going to lose it," said Sorensen, who will be in Evans' wedding party when he gets married next summer. "He looked at me and engaged and I just stood there and he was going to hit me. And we ended up scoring on the power play."
Calgary led 3-2 after the first quarter and 7-4 at half-time.
"We played well in the first half but then we got undisciplined and I thought they outworked us in the second half and that's the M.O. of this league, if you get outworked, they're going to put the ball in the net," said Roughnecks captain Andrew McBride.
Notes: The Scotiabank Saddledome crowd was announced at 10,008… Washington coach Chris Hall, who was the Roughnecks original coach and won a Champion's Cup with them in 2004, coached his 150th NLL game. He is just the fourth coach in NLL history to reach that milestone… Dickson's first goal was his 100th of his career… Dickson is one short-handed goal from matching the NLL single season record of seven. With 12 in his career, he's tied with Tracey Kelusky for the franchise lead… Daryl Veltman (lower body) did not play for the Roughnecks… The Roughnecks are 7-5 against Washington, but just 1-4 at home against them.