But as the big defenseman skated by the goal, he realized the puck had gone in.
Weber took a pass from J.P. Dumont and fired a shot from the slot that trickled through Mason's right side and into the net.
"I thought (Mason) squeezed it," Weber said. "I thought he got enough of it to squeeze and then as I skated by, I saw it running down his leg. I was very fortunate."
The win gave Nashville, coming off a 2-1 overtime loss at home to the Blues on Thursday night, two crucial points in the Western Conference standings in the race for the eight playoff spots. The Predators are 10th in the conference with 60 points, while St. Louis is 13th with 58.
Rinne said the shutout is no big deal. It's the points that count most.
"It's a prize for the whole team," Rinne said. "The team defense today was really rock solid and we didn't give up too many quality chances."
The goal was Weber's first in 15 games.
Mason stopped 21 shots against his former teammates.
"It just kind of bounced out to (Weber) and he just kind of sweeped at it," Mason said. "It just kind of caught me off guard there. It's just the way the play happened. I squeezed it and it dropped behind me and snuck in."
The game had a playoff-like atmosphere.
"A real tight game," Blues coach Andy Murray said. "We certainly had ample opportunity to score some goals and we didn't do that. ... It was a one-goal hockey game and whoever was going to score that next goal was going to win the game. That's the way it felt for a lot of the hockey game tonight."
The Predators had the best chance to break the scoreless tie in the second period, but David Legwand's backhander in front of a crowded crease with 14:25 to play in the period hit off the near goal post.
The second period nearly ended in disastrous fashion for the Blues, as Nashville's Joel Ward nearly fired the puck into an open side after Mason casually played the puck toward the right corner. Ward caught up with the puck, but fired a shot off the side of the post as time expired.
"It was an excellent hockey game," Predators coach Barry Trotz said. "It was a typical St. Louis and Nashville game -- it took more than 60 minutes."
- This was the final meeting of the season between the teams and third in 10 days.
- Ten games between the Blues and Predators in the last three seasons have gone to overtime or a shootout, including four this season. It also was the second game that was scoreless in regulation.
- Murray reached 300 career victories Thursday night.
- Predators F Steve Sullivan has three goals in four games after not scoring in his first 16 games this season.
- McDonald has seven points (two goals, five assists) in seven games after missing 36 games with a fractured ankle.
- Predators F Radek Bonk left the game in the second period with an upper-body injury.