John Marquis has scored eight goals this season - including strikes in all his side's three big home wins over Birmingham City, Wrexham and now Mansfield
Shrewsbury Town had defender Toto Nsiala sent off - but still recovered to beat Mansfield Town and climb off the bottom of League One.
Will Evans put the visitors ahead after just five minutes however Nsiala was shown the red card for a foul on Lee Gregory on 34 minutes.
But Marquis levelled on 54 minutes, heading home Josh Feeney's cross.
Then, just nine minutes later, George Lloyd got the winner, finding the bottom left corner, from an Alex Gilliead through ball.
Nigel Clough's Stags drop to 14th after their fourth straight league defeat, while Gareth Ainsworth's Salop go above Cambridge, within five points of safety.
