"I knew it was there, but I was trying not to think about it," Demmerly said. "I figured, 'If it happens, it happens.' It's just a statistic. I was more concerned about the game."
Demmerly finished with four goals, and Jake Dean, Cory Munger and Kyle Borbi added two each for seventh-seeded Shawnee (15-5), which won its sixth in a row and 12th in its last 13 games.
The Renegades advanced to play at second-seeded Ridgewood on Thursday.
"I can't wait to go up there and play," Demmerly said. "I think we have a very good chance of beating them."
Ryan Davidson collected two goals and an assist, and goalkeeper Conor Beers made 12 saves for 10th-seeded Kingsway (15-6).
The Dragons broke to a 2-0 lead but couldn't sustain the pace against their Olympic Conference Patriot Division rivals.
"We played hard. That wasn't the issue," Kingsway coach Sean Dunn said. "But there's a difference between playing hard and playing smart. We made some mistakes, and they capitalized on them."
After Kingsway's early surge, Shawnee tightened its defense and held the Dragons to one goal over the next 42 minutes.
Shawnee received strong work from keeper Reece Tursi (seven saves) and defender Sean Murray, among others.
"It was our best defensive performance of the season," said Shawnee coach Tim Gushue, whose team had beaten Kingsway by 10-8 and 18-9 during the regular season.
Shawnee controlled the pace of play with its offense, limiting turnovers and maintaining possession for long stretches.
"We've been a little run-and-gun lately, but we knew we needed to slow it down," Demmerly said.
Demmerly, who plans to play lacrosse next year for Goucher College in Towson, Md., nearly scored his 200th goal with 0:05 on the clock in the first half, but hit the post.
He took care of business early in the third quarter, dodging a defender behind the net and racing in front to score his 200th.
"It felt awesome," Demmerly said of the 200th goal. "It's a big milestone for me. I was so excited, and my teammates were so excited. I loved it."
Kingsway 2 1 0 1 – 4
Shawnee 2 4 4 1 – 11
Goals: K-Ryan Davidson 2, Kyle McLaughlin, Gino Frederico; S-Owen Demmerly 4, Jake Dean 2, Kyle Borbi 2, Cory Munger 2, Eric Meyer.
Saves: K-Conor Beers 12; S-Reece Tursi, 7, James Bickel 1.
Contact Phil Anastasia at 856-779-3223, panastasia@phillynews.com, or @PhilAnastasia on Twitter. Read his blog, "Jersey Side Sports," at www.philly.com/jerseysidesports