The victory pushed the sad-sack Blue Jackets -- the only current team to never have been in the playoffs -- into a tie for fifth place in the Western Conference.
"The most important thing for myself is getting us in a playoff position. And we did that tonight," Mason said. "Obviously, we just want to keep moving forward with it. Shutouts are nice to get on a personal note, but they don't really mean anything in the end."
Mason is 19-11-2 with a league-best 1.98 goals-against average in 32 games. He's fifth in save percentage (.928) and has allowed two or fewer goals in 19 of his past 27 starts.
"Steve Mason had an outstanding game," said Voracek, who redirected Michael Peca's shot at 3:55 of the second period. "He made a couple of big saves in the third period. It doesn't matter if it's 1-0 or 5-4; it's still two points for us."
Mason was at his best in the third period when he weathered three Ottawa power plays and turned away eight shots.
"When we did get some decent chances, he (Mason) made some big saves," Senators wing Dany Heatley said.
The best saves came on Ottawa's final flurry with a man advantage.
Alexandre Picard's hard shot was stopped by Mason with just under 6 minutes remaining. Mason stayed on the ice, wincing in pain before getting up and continuing.
He underwent arthroscopic surgery on his left knee on Sept. 23, 2008, causing him to start the season in the minor leagues. This time he appeared to favor his right knee, flexing it after the Blue Jackets cleared the puck when play resumed.
"I got hit in the knee," he said. "It just kind of completely skipped a pad and went on my knee. It didn't feel too good. My pads are pretty crappy right now. I'll be getting some new ones pretty soon, hopefully."
So precious is Mason to the franchise these days, you can bet the Blue Jackets will try to overnight new pads before Mason takes the ice against Dallas on Saturday night.
With just over 5 minutes left, Heatley had the puck and all the time in the world at the right doorstep after taking another backdoor pass. He waited and waited for the 6-foot-4 Mason to go down before trying to go high over Mason's shoulder, but Mason smothered the puck.
"Mase had to make three big saves in the third period," Columbus coach Ken Hitchcock said. "He's OK. What are you going to say? He's a hockey player. You accept the fact that you have a hammer."
The 20-year-old Mason has started 16 straight games for the Blue Jackets, winning 11 of them.
Five of Mason's seven shutouts have come against the Eastern Conference. He's 7-1-0 with a 0.74 goals-against average and .972 save percentage against the East.
Ottawa's Alex Auld, playing for the first time since Jan. 6, had 24 saves and kept the Senators -- who had won their last two road games -- in the game.
"Against that team you're not going to create a lot of scoring chances, but in the third we did have a couple of quality ones," Ottawa coach Craig Hartsburg. "That's what it comes down to against a team like Columbus -- you need to score on your chances because you're not going to get many."
Mason saw to that.
Columbus was 0-for-6 on the power play. Ottawa has killed off 24 of its last 25 penalties. ... Blue Jackets LW Fredrik Modin returned after missing a game because of a a shoulder injury. ... The Senators were making their first trip to Columbus since Dec. 10, 2006, a 6-2 Blue Jackets win. ... The win guaranteed Columbus of a winning record in January, marking the first time in franchise history it has put together three straight winning months.