Burton's lead at the top of Sky Bet League One was cut to two points after they were held to a goalless draw by fellow promotion chasers Walsall in a dour Staffordshire derby.Nigel Clough's team were unable to turn their possession into a much-needed victory although they remain six points clear of third-placed Gillingham and the Saddlers in fourth, with Wigan closing the gap after defeating Bury.After a cautious and uneventful first half-hour, openings came at both ends in quick succession.Burton's Mason Bennett was denied a clear shot on goal by Jason Demetriou's last-ditch tackle before John McLaughlin's sprawling save thwarted Romaine Sawyers.The visitors looked increasingly assured as half-time approached and it took a fine reaction save by McLaughlin to prevent Paul Downing from opening the scoring.The Burton goalkeeper was quickly in action after the break, smothering an angled shot by Milan Lalkovic.Stuart Beavon fired narrowly after a jinking run as Burton tried to seize the initiative, but McLaughlin had to come to the rescue again in the 70th minute when he blocked Demetriou's shot with his legs.Lucas Akins wasted a late chance for Burton when he headed into the arms of Neil Etheridge.