Opposition view: Costello admits Saints deserved their win against Munster

The black, green and gold secured an enthralling 34-32 success that means they will finish top of Pool 3.

Munster pushed Saints until the end, but a breakdown steal from Henry Pollock put the seal on the victory for the home side.

And Costello said: “To be fair I think they deserved it.

"I think they capitalised really well on the yellow card (for Munster No.8 Gavin Coombes), that period just before and after half-time.

“They scored 12 points, and we struggled to get our hands on the ball in the third quarter and we knew that was going to be really important.

“So I suppose it gave them a lead, we got close enough in the end but I think the bottom line is we weren't good enough and didn't deserve to win it.”

Tom Seabrook scored a hat-trick for Saints as they fought back from going 15-5 down during the first half.

“We got a huge bounce off the bench last week (in the win over Saracens), bringing four subs on, we were looking for the same impact today," Costello said.

"Probably got disrupted with Gavin getting sin-binned and we looked to get the four of them on with Gavin, looking for that swing in momentum. We didn’t quite get it.

“To be fair to them, I thought the next 10 minutes they were really strong. We struggled to get our hands on the ball, when they’ve got that much ball they’re a very, very dangerous side.

“The big thing was that third period. They were really good ball in hand, we were inaccurate, gave away a couple of penalties that allowed them to go deep into our line.

"They were lethal, as we know, off strikes. When you give them that much field position through our own inaccuracies that’s what’s going to happen.”

Munster skipper Tadhg Beirne had a huge game in a losing cause.

And Beirne said: “When we’re good, I think we’re very good. The problem is when we’re poor we’re being very poor.

“We need to be very good for a lot longer periods in the game and that’s the frustrating thing.

“There’s belief in this group with what we can do, it’s about putting the foot down and doing it ideally for 80 minutes. We’ll be hard to live with when we do do that. I think we showed snippets of that in today’s game.

“To still concede five tries, it’s pretty disappointing. What might look like a really good try to the average supporter, we’re looking at that as a terrible try to concede in terms of our systems. That’s the stuff that we’ll be frustrated with.”