Backes and McDonald broke a 42-year-old franchise record by scoring 6 seconds apart early in the first period, and the St. Louis Blues went on to a 5-1 victory over the slow-starting Ducks on Monday.
"They've had trouble scoring goals, so it was good for us to get off to a quick start, get on them quickly and put a couple of goals in," said Brad Boyes, who got the second assist on Backes' goal. "The quick start was something we wanted to do."
Backes scored at 3:53 when he sneaked down the left side after an Anaheim turnover and fired in David Perron's centering pass. T.J. Oshie won the ensuing faceoff at center ice, got the puck back from Patrik Berglund in the high slot and fed it to McDonald near the left circle.
McDonald beat Ducks goalie Jonas Hiller with a wrist shot at 3:59 to make it 2-0.
The two goals in a 6-second span broke the previous club record of 7 seconds apart set by Don McKenney and Frank St. Marseille on Jan. 24, 1968, against the Minnesota North Stars.
"To be rewarded that early, it really helps you to stick to your game plan and I thought we did a good job throughout the game to do that," Blues defenseman Barret Jackman said.
"It was full engagement from start to finish," St. Louis coach Davis Payne. "We've been on the other end of that."
Saku Koivu had the only goal for Anaheim, which lost all three games on its season-opening road trip. The Ducks were outscored 13-2, with Koivu scoring both goals.
Anaheim coach Randy Carlyle was philosophical about his team's performance on the trip.
"Obviously, the sun is going to come up tomorrow -- we hope," he said. "What you have to do is take a self-analysis of what we can do better. There's lots of areas for us to improve in as a team."
Anaheim goalie Hiller was busy again, making 30 saves on 34 shots. Hiller, who faced 92 shots in the previous two games, was lifted in favor of Curtis McElhinney after D'Agostini scored his first goal on a slap shot from the right circle to make it 4-1 with 4:09 left in the second period.
"You always want to get that first one and get it off your back," D'Agostini said. "Then you can start playing."
McElhinney stopped 18 of 19 shots in his relief role.
Ducks forward Corey Perry said despite the lopsided stats, the team is not that far away from success -- with plenty of time to get things right.
"It's only three games," Perry said. "There's 79 more to go. But it's tough to start the season 0-3.
"They had 50-some shots today, too, and that doesn't help. The puck's going the other way. We just need to get some of those on our stick and get the garbage goal we need to get us going."
Blues forward Cam Janssen is expected to miss two weeks with a concussion and bruised sternum he received when he was accidentally hit by his own teammate, Brad Winchester, in Saturday night's game against Philadelphia. Janssen was replaced on the roster by Ryan Reaves, who was given a game misconduct in his first NHL game when his jersey came off in a fight with Kyle Chipchura. ... The Ducks allowed 145 shots in their first three games. ... McDonald, who won a Stanley Cup with Anaheim in 2006-07, has six goals and nine points in nine games against his former team. ... Anaheim was 2-0 in day games last season.