The Vegas Golden Knights (7-3-3) led 2-0 after the first period but gave up six goals in the final 40 minutes of action, falling 6-3 to the Tampa Bay Lightning (7-5-2) Thursday night at T-Mobile Arena. Ivan Barbashev scored twice, and Mitch Marner had three points, but it wasn’t enough to get the best of the visiting Lightning, who completed the sweep of the season series.