Saints bossed much of the game but were undone by their failure to gather two high balls, which cost them a total of 14 points.
George Furbank had a chance to save the day for the black, green and gold as he lined up a penalty with the final kick of the match, but his effort drifted agonisingly wide of the right post.
That allowed Sale to celebrate the narrowest of away wins, pushing them above Saints in the Gallagher Premiership table.
But Sharks boss Sanderson was quick to acknowledge that his side did not deserve their victory.
"We probably should have lost," Sanderson said.
"You can only play as well as the opposition allow you to, and that was probably our worst performance in four or five weeks.
"But the old cliché stands that if you can play badly and win, you're in a good place, so we're in a good place.
"Sometimes I hate starts like we had (Sale went 10-0 up inside five minutes) because I could feel the lads felt it was easy and then they just relaxed from the kick-off.
"Saints got a try and then we were only three points ahead so that made it not such a good start."
Sale twice troubled makeshift Saints full-back Rory Hutchinson with the high ball, with kicks leading to tries for Arron Reed and Rohan Janse van Rensburg.
And Sanderson feels the hard work paid off for his side in that regard.
"We work a lot on our kicking game and we work hard on judging it so it's not luck," he said.
"It's training and hard work that paid off in some of those high balls."