Morrison hit the post with 4:45 to go, and Miller steered away 13 shots in the third period.
Gerbe added an assist, and defensemen Steve Montador and Henrik Tallinder also scored for the Sabres (17-9-2), who snapped a two-game skid.
The Capitals (19-6-6) were shut out for the first time this season - and the first time since a 3-0 loss to Columbus exactly 11 months earlier.
Oilers 3, Lightning 2 - Zack Stortini scored his third goal of the season and had two fights as Edmonton stopped host Tampa Bay, which has lost six of seven.
Stortini won a battle behind the net for the puck, moved toward the slot, and scored to give Edmonton a 3-2 lead at 11:07 of the second period. He fought Zenon Konopka late in the first and again during the second.
Edmonton also got goals from Tom Gilbert and Dustin Penner. The Oilers have won four straight on the road for the first time since Nov. 14-Dec. 8, 2005.
Blackhawks 2, Rangers 1 - Dustin Byfuglien skated down the left side past defenseman Matt Gilroy and beat Henrik Lundqvist with 1:17 left in overtime for host Chicago.
The Blackhawks tied the game with 5:55 left on a power play when Jonathan Toews chipped in a goal after a scrum in front of the net as Chicago finally got one past Lundqvist.
Christopher Higgins scored for Rangers in the first period and it appeared Lundqvist would shut out the Blackhawks. He finished with a season-high 39 saves. The Rangers lost for the fifth time in six games.
Blues 1, Red Wings 0 - Brad Boyes scored early and Ty Conklin held on late for a shutout, leading St. Louis to its third straight road win.
Conklin made 42 saves against the team that couldn’t afford to keep him around as a backup.
Jimmy Howard gave up a goal on the second shot he faced 1:56 into the game and finished with 25 saves, getting the start ahead of slumping Chris Osgood.
Maple Leafs 3, Islanders 2 - Jason Blake knocked home a bouncing puck with less than five minutes left for host Toronto.
