Wales led by 21 points at one stage and ended up scoring four tries, two of them from Ospreys flanker Jac Morgan.
“We got everything we wanted from the start of the game. I thought we built the game nicely and got ourselves in a situation where we should have won the game,” admitted Pivac.
“Clearly we took advantage of their ill-discipline and the roles were reversed when they did the same to us. It was frustrating to all the players, although I can’t fault the effort the boys put in.
“We said after last week we wanted more physicality and we wanted to go out there and express ourselves. For large parts we did that, but we could not bring it home.
“The result was disappointing but there was a lot of good stuff to take out of that game which is a positive for us moving forward.”
The defeat meant Wales ended the four game series with just one win, against Argentina, and ended 2022 with a record of played 12, won 3, lost 9.
“The heat was on me during the week. I had to try and take it off the boys and they played large parts of that game exactly as we wanted them to,” added Pivac.
“We review every competition and we will do that now. We have to take the positives out of the competition. Things that did not go well we can iron out.
“You saw that when we get things right we are a dangerous team. We have more players to come back into the side.
“There’s a lot of luck in this game. When we won the Championship, a lot of it went our way. It feels that at the moment, in tight situations, it hasn’t.
“We just have to keep believing and working hard because I think everyone would agree there was a marked improvement in that performance. I’m just focusing on our team and what we asked for during the week and what the players wanted to deliver on, and I felt they did that for the majority of the game.
“It’s one of those ones which is very tough to take. Rugby can be very cruel at times.”