Mark Arcobello scored his second goal of the game with 2:00 left.
Tyrvainen scored his second goal, an empty-netter with 1:24 remaining for a commanding three-goal lead. Garrett Stafford added a power-play goal with 15 seconds left.
The Barons, though, played catch-up most of the game other than a short lived 1-0 lead early in the second period.
Oklahoma City fired 46 shots at Texas goalie Cristopher Nilstorp, who entered the game with a 1.90 goals against average in the playoffs.
“We finally started capitalizing on chances,” Nelson said. “We had plenty of chances in the second period. Nilstorp made some great saves. It finally worked out for us. We kept shooting and driving to the net.”
The Barons have been relying on goaltender Yann Danis, an improved defense and solid penalty killing unit. In Game 4, they needed offensive production that included two goals from Tyrvainen, who plays on the fourth line.
“That's what wins games in the playoffs,” Fedun said. “You have to find different ways to win. On a night we weren't able to stifle them as much as we have been it was nice to explode a little bit offensively.”
The Barons had to finish the regular season 13-3-3 just to get in the playoffs, but they've been the AHL's hottest team the past two months.
“We want to finish it. They're still very much in this series, but we don't want to let them hang around,” Arcobello said. “If we can bring the effort like we did tonight, we should be in good shape.”