Ivan Provorov pulled the Blue Jackets within 3-2 at 7:01 of the third period when he knocked in a loose puck during a scramble in front. The Capitals challenged for goalie interference, but the goal was upheld.
Lapierre took a pass from Milano and lifted a backhand past Merzlikins on a breakaway at 13:34 to make it 4-2.
“Been working on my backhand a little bit, just trying to get comfortable,” Lapierre said. “So, it was kind of like a hope shot more than anything and it ended up going through, so I was super happy.”
Justin Danforth scored on a rebound in front at 15:48 for the 4-3 final.
Columbus outshot Washington 16-9 in the third but failed to convert a late power play after Capitals defenseman Trevor van Riemsdyk was called for holding at 17:26.
“I thought we looked good there in the third, had a lot of good looks,” Gaudreau said. “But they found a way to make it a two-goal game and we made it a one-goal game again. It's hard.”
Gaudreau gave the Blue Jackets a 1-0 lead at 3:27 of the second period with a wrist shot from the high slot during a delayed penalty.
Milano tied it 1-1 at 5:05 on a sharp-angled shot from the bottom of the left face-off circle after a no-look, cross-ice feed from Protas.
“That line was the difference in the game for us,” Carbery said. “We weren’t generating, and then that line takes over and scores and sort of gets some life into the building and into our group. And backs it up again and again. They were fantastic.”