ST. LOUIS -- A season-long six-game homestand ended much like it started for the Blues.

And the answers they were searching for then have pretty much remained the same: the Blues are inconsistent, they can't sustain any kind of strong play, and Jake Allen, who got the start Tuesday in the David Backes reunion tour against the Boston Bruins, is a mess right now.

Allen was pulled for the third time on the past five starts -- albeit one for precautionary reasons due to injury -- after allowing three goals on 11 shots, and the Bruins got the best of the Blues 5-3 on Tuesday before 19,342 at Scottrade Center.

The Blues (21-15-5) hit the midway point to the season Tuesday; they fell to 6-8-1 the past 15 games and now must try and tackle their road woes, where they're 5-10-1, in the second half of the season, where they play 25 of the remaining 41 games.

Backes received the rousing video tribute; he didn't score nor was he involved in the scoring, but his teammates helped provide the inspiration needed to come away with a win.

Brad Marchand and David Pastrnak each had three points. Marchand had two goals and an assist and Pastrnak had three assists for Boston, which led 3-0 after the first period on goals from Frank Vatrano, Brandon Carlo and Marchand.

Vatrano and Torey Krug each had a goal and assist for the Bruins (22-17-5), who got 14 saves from Tuukka Rask and improved to 2-0-1 on their four-game road trip.

"It's special, but certainly something I've never experienced before and it was great to be back in the building and thankfully we jumped out to a decent lead because trying to bottle up everything on the ice was tough, no question about it," Backes said, "and the guys played amazing and they were able to get two points out of the game. I had the best seat in the house for most of the third period but that's part of the game."

Backes played at Scottrade Center for the first time since signing as a free agent in the offseason. He played 727 regular season games with St. Louis. Backes didn't have a point but had 17 penalty minutes after a fight with Blues defenseman Joel Edmundson in the third.

"I felt like they were trying to get the game back by trying to intimidate us and hitting us all over the place and I don't think it really matters how it happens," Backes said. "It's kind of, we've got to put an end to this, so I tried to put an end to it and the guys killed the penalty off and did a great job and got the two points."

Colton Parayko, Patrik Berglund and Kyle Brodziak scored for the Blues, who finished a season-long six-game homestand 3-3-0. Carter Hutton made 26 saves after replacing Allen to start the second.

The Blues have alternated wins and losses the past nine games.

"It's frustrating," Blues defenseman Alex Pietrangelo said. "We're tired of talking about it, we're tired of answering the questions from outside our locker room. We need to be better, especially early on. I thought at points in the second and third, we showed spurts of what we had to do, but we've got to find a way to do it right from the start."

Said coach Ken Hitchcock: "I think there's a couple things. I think the game was just a game until the second goal went in. Then it got away for a few minutes on us. I thought overall their level of desperation to defend was greater than ours. That's why they had so many – if you look at the overall shot groupings they're not very far off, but what did they have, 20 blocked shots? Their desperation to block shots, their desperation to defend was greater than ours and it showed up in the game. They cut our space down in the offensive zone, frustrated some of our top players, played us really hard in their own zone, led to some exits that they got out of there, there's a couple of goals we'd like to have back but I thought the level of desperation was higher for their side for more minutes than it was for ours. We made a big push at the end but they were higher."

Vatrano gave the Bruins a 1-0 lead at 8:19 of the first period with a power-play goal after a failed clearing attempt by Brodziak despite a good effort to get to the puck.

Carlo scored after his shot ricocheted off the back boards and then off the side of the net before Allen kicked it into his own net for a 2-0 Bruins lead at 15:20.

"I didn't really see the guy shoot it, but I picked it up as it goes back, I did my routine normal save," Allen said. "To be honest, I thought it was going to go on the ice and I've done it 100 times, kick it in the corner and it bounced, rode up the side of the net and it hit my skate and went in. I don't know if I really would have done anything different and just hopefully it stayed on the ice."

It went from bad to worse as Marchand beat Allen with a shot from the right circle short side at 17:52 to make it 3-0.

"This is really tough for me right now," Allen said. "The crazy thing is I don't feel bad on the ice. I feel like I'm practicing well, I feel good out there. It's just pucks are getting behind me and I've got to find a way to stop that sooner than later. We don't have a lot of time before other teams are going to catch up to us or we're going to put too much distance between ourselves and the next two in front of us.

"It's frustrating for me honestly. I've really always had high expectations for myself. I always set the bar really high. It's tough even when you play well and you don't meet those expectations. I've got to be better. 'Hutts' I thought did an amazing job. He gave us a chance. He had lots of shots. Really unfortunate for him to get that loss. It's a stupid rule, I think. He gave us a chance to get the win and he ends up getting the loss. I think it should be all me, but he was awesome tonight."

Hitchcock made the move to Hutton, who took the loss.

"He's not stopping the puck," Hitchcock said of Allen. "... He's having a tough go of it. We can just jump all over him or rally around him. We have a choice. He's having a tough time right now. Thank God 'Hutts' is playing hard or we'd be in really tough shape. He's having a real tough go and I don't think anybody anticipated this, him or us. It is what is, we have to deal with it, I can't really get into the technical part because I'm not sure what it is, but obviously the goals are … for whatever reason, it's just too much to look at. Probably some of it is confidence, dealing with adversity for the first time things haven't gone smoothly in his career. He's going to have to battle like the rest of us. But I think we can help out too. We can play better in front of him. We're going to have to rally around him. We have to start playing … to me, I'm not sure how everything is connected but there's not enough respect for defending right now. We're trying to outscore the other team, we're trying to defend moving forward, we're not getting in the lanes like we have to. I think it was a little bit of an eyeopener. We had a lot of zone time but never got any activity there because they were desperate to get points. They've had a lot of games where they've lost and played well and they put on a desperate show today. Obviously with the Backes situation they were emotionally charged, and I thought that was the small difference in the hockey game."

Krug greeted Hutton by scoring Boston's second power-play goal in as many chances to make it 4-0 at 1:31 of the second on a snipe from the high slot off the cross bar and in.

Parayko's first of the season, a wrist shot from the right circle on the power play at 3:57 of the second, made it 4-1.

Berglund's power-play goal from the slot with 9:46 to play cut Boston's lead to 4-2. Marchand scored an empty-netter with 1:17 remaining, and Brodziak scored with 25 seconds remaining.

There was fight in the end, but once again, having to chase the game sends this team into stretches where it changes what makes it go, and in the end, the result is inferior.

"I don't know if it's a lack of energy, but mentally, we just weren't where we needed to be," Pietrangelo said. "I thought we played hard as the game went on. Mentally, we just weren't sharp at the start. Whenever we're losing these games, we're getting ourselves behind here in the first or second and we're having to crawl our way back. It's got to start right away; we've got to set the tone from the beginning."