Leyton Orient goalkeeper Jamie Jones denied Preston a third straight home win with a string of fine saves in a feisty goalless stalemate at Deepdale.
Preston manager Simon Grayson was forced into making a change after 20 uneventful minutes as Stuart Beavon was stretchered off after clashing heads with Nathan Clarke, which prompted a lengthy stop in play.
But Preston nearly took the lead from the restart, Bailey Wright forcing Jones to palm over from 12 yards.
The Lilywhites threatened again the 37th minute, a mazy Lee Holmes run setting up Jack King, but his shot was blocked much to Orient's relief.
Jones' stunning fingertip save stopped King's 18-yard effort in the 43rd minute and Clarke cleared after the ball had crashed back off the crossbar as Preston could not find a way through.
The Lilywhites were the side creating the chances, but King headed over when unmarked just eight yards out after 50 minutes.
And Nicky Wroe's curling 20-yard effort tested Jones with 10 minutes remaining, but neither side could find the breakthrough they were looking for as Orient's three-match winning run came to an end.