PNE were beaten 4-1 by Rovers, their heaviest home defeat since the opening day of the season.
Lowe’s men were second best from start to finish against the visitors who raced into a 2-0 lead inside 12 minutes through goals from Sam Gallagher and John Buckley.
Alan Browne reduced the arrears briefly before Darragh Lenihan made it 3-1 before half-time.
Rovers scored their fourth goal early in the second half through Lewis Travis.
North End manager Lowe said: “It definitely wasn’t the night I was looking for, I didn’t really see that coming.
"The lads had trained particularly well, we had three days build-up to it.
"We can’t give two goals away in 12 or 13 minutes, that can’t happened against any team.
"With all due respect, Blackburn weren’t in great form, we felt we could jump them and get on to them early with being at home.
"It was the opposite way round to be fair, they did that to us and were on the front foot. I thought they wanted it more than we did.”
Lowe was composed in the post-match interview but had talked bluntly with the players in the dressing room.
"I’ll stick with the lads through thick and thin, I’m never going to throw them under the bus in the media,” said Lowe.
"I’ve discussed a few things in there with them, but I didn’t see that coming – they have been different class for me.
"But I need to get it in their heads that the holidays are not just round the corner, we have got two important games to finish the season and we want to finish with as many points as possible.
"I have told them that in no uncertain terms. I could sit here all night and talk with you about what went wrong, ifs and buts and what not, but ultimately we weren’t at the races tonight.
"We have been punished for that.
"Give credit to Blackburn too, they jumped all over us. They got the first goal and then the second goal quickly.
"At 2-0 down I still believed in the group that we could get a goal back and we did, Browney’s shot ricocheted in.
“If we had stayed at that tempo and got another goal, who knows. But we were passive in so many ways, the passing wasn’t great, the aggression in trying to get the ball back wasn’t great.
"We were dropping into areas where we didn’t want because balls were coming in for Diaz and Gallagher. I thought we found it tough.
"Again we conceded and 3-1 was a tough scoreline at half-time. We had to change shape again for the second half but I said to the group I won’t be changing shape too often because I prefer a 3-5-2 – what will change is the personnel.
“I feel the formation works but we have to be better in that formation, we have to be better in transitions, we can’t give the ball away.”