Tranmere inflicted a surprise 1-0 defeat on promotion-chasing Bradford with their first away win for five months.
Josh Hawkes scored the only goal at Valley Parade with a penalty to extend their unbeaten run under interim manager Andy Crosby.
Bradford, who had won their previous 10 home games, missed the chance to move level on points with leaders Walsall.
Home captain Richie Smallwood went close with a 25-yard drive and George Lapslie sent a glancing header wide.
Brandon Khela was not far away with a curled attempt from outside the box as the home side continued to press for an opening goal.
Jamie Walker thought he had got it just before half-time, but was thwarted by Tranmere goalkeeper Luke McGee who stuck out a leg to block.
Tranmere’s threat had been limited to one hopeful effort from Kieron Morris, but they took the lead after 56 minutes with Hawkes scoring from the spot after Jack Shepherd fouled Harvey Saunders.
The game was halted for 12 minutes for a medical emergency involving a supporter.
Tranmere held on for their first away win since beating Bromley on October 19 – a run where they picked up just one point in 11 matches.
