Saracens boss Mark McCall was left ruing a ‘horrible six minutes’ after his side fell to defeat against Saints on Saturday.
McCall’s men had been in command of the affair at stadium:mk after two Chris Wyles tries.
But England No.8 Billy Vunipola missed a huge chance to extend their lead before the break and was then forced off with an ankle injury.
His replacement, Jackson Wray, was on the field for less than two minutes before he was knocked out by an accidental clash of heads with a team-mate.
And Saints took charge after the break, storming back from 17-13 down to secure a vital 25-20 win that takes them a step closer to a home play-off semi-final on May 23.
“We started the game well, we were clinical with first few scores that we got but then we had a horrible six minutes where Billy drops the ball over the line which would have made it 21-10,” said McCall.
“Then Billy rolls his ankle, and it was a big blow to lose a player like him, then his replacement is off two minutes later. It was a poor six minutes.
“That being said, we were 20-13 up after 25 minutes but we didn’t deal with a restart, then we got penalised then Maro Itoje was sin-binned and the momentum of the whole game swung. In fairness to the Saints, they took advantage of that brilliantly.
“I thought it was a two-point game and we when we fared their defence in the last 20 minutes, we could have been a little bit smarter.
“I don’t think we managed our energy well enough in the last 20 minutes and I still think there was a game to be won.
“If we’d been a little bit smarter we still could won the match.”