After Joel Ward put the Sharks ahead 2-1 with an even-strength goal at 11:49, Couture scored on the power play to make it 3-1 with 4:20 left to play. Couture darted down the slot, took a pass from Joe Pavelski and beat goaltender Pekka Rinne from close range.
"I started in the neutral zone and was able to step inside on [Predators defenseman Shea] Weber, and [Rinne] kind of lunged at me there," Couture said. "[Pavelski] made a great backhanded pass. I just tried to elevate.
"I had a couple chances earlier where I didn't elevate the puck, and he made the saves. I was just trying to get it up and over the glove."
The Sharks actually built some momentum on their first power play, late in the second period. Their top power-play unit of Joe Thornton, Pavelski, Brent Burns, Patrick Marleau and Couture had the puck in the Predators zone for the first 1:48 and put five shots on net.
Going into Game 1, the Sharks appeared to have the edge on the power play. They were third in the NHL with the man-advantage (22.5 percent) during the regular season, and they scored five power-play goals on 21 attempts in the first round against the Los Angeles Kings.