Lalime made 22 saves in the Sabres' 7-1 rout of the Tampa Bay Lightning on Saturday night, giving Buffalo its first playoff berth since 2007.
"To get in with the game we played was real good," Buffalo coach Lindy Ruff said. "I might even smile."
Lalime, who was 0-4-1 with a no-decision since posting win No. 199 against Pittsburgh on Dec. 29, became the 66th NHL goalie to reach the milestone.
"It's pretty nice to get there," Lalime said. "It was a hard one to get. It just means I'm old, probably."
The Sabres will play meaningful games into mid-April for the first time in three seasons.
"The last year we've been talking about doing that," Lalime said. "Now that we're in the playoffs, we want to set the bar high and finish strong."
Buffalo's offensive outburst -- its highest goal total since a 7-2 win at Phoenix on Jan. 18 -- was led by Derek Roy, who recorded his fourth NHL hat trick. Paul Gaustad, Jochen Hecht, Jason Pominville, and Adam Mair also scored for the Sabres, who have won five of six.
"It was a great night," said Roy, who scored twice during power plays. "We scored two goals right off the bat and could have had a couple more."
Buffalo then broke the game open with a pair of power-play goals during a 5-minute advantage. Tampa Bay captain Vincent Lecavalier was assessed a major penalty -- along with an automatic ejection -- for spearing Tim Kennedy. Roy and Hecht scored 50 seconds apart to put the Sabres up 3-0.
Niittymaki was then pulled, having given up three goals on six shots in the first 8:52. His replacement, Mike Smith, made 16 saves.
"We didn't come ready to play," Lightning forward Martin St. Louis said. "From the get-go, you could tell we were just trying to feel our way instead of initiating and dictating. Next thing you know it's 3-0 and they're a tough team to come back against."
In the second period, Pominville redirected a pass at the corner of the goal mouth seven minutes in. Roy notched his second of the night on a backhand flip less than 3 minutes later. Mair then scored with 8:44 left, duplicating Pominville's positioning and tapping in an easy goal.
Steve Downie scored for Tampa Bay, spoiling Lalime's shutout bid with 43 seconds left in the middle period.
Roy completed his hat trick with a power-play goal 6 minutes into the third. He connected on a slap shot from between the circles.
"It's an embarrassing loss," said Tampa Bay coach Rick Tocchet, whose team has lost six of eight and fell eight points behind the postseason cutoff in the Eastern Conference. "We're in high critical games. You've got to backcheck like it's the last shift of the season. Our defense has to box out like it's the last game of the season. It's embarrassing some guys packed it in."
Rookie Tyler Ennis, who scored in his only other NHL game Nov. 14 at Philadelphia, had two assists.
Buffalo played without C Tim Connolly and RW Patrick Kaleta. Connolly injured his foot about a week ago and it flared up. Kaleta has an upper body injury. ... Pominville, with a goal and two assists, surpassed the 300-point milestone for his career. ... The Lightning recalled D Vladimir Mihalik from AHL Norfolk, and he made his season debut. He played in 11 NHL games last season.