An injury-time strike from Arthur Gnahoua saw Sky Bet League One pacesetters Shrewsbury snatch a 2-1 win over Doncaster.The Shrews were on course to maintain their unbeaten status when Joe Riley cancelled out Tommy Rowe's opener for Rovers in the first half.But it got even better for them when substitute Gnahoua strolled through the Doncaster defence and slotted home deep into added time.The home side did take a deserved lead after 35 minutes when Rowe drilled in from 20 yards after a fine lay-off from John Marquis.But before the hosts could settle on their lead, they lost it a minute later. Full-back Riley smashed the ball in off the far post from the corner of the box after Shrewsbury surged up the pitch from the restart.Carlton Morris should have put Shrewsbury ahead before the break but headed straight at goalkeeper Ian Lawlor.Doncaster were the stronger side after the break with Alfie May, Marquis and Rowe all good having chances to put them ahead.But Gnahoua broke home hearts with a good finish in stoppage time.