Cheltenham’s five-match winning run was brought to an end as they were held to a 0-0 draw by Port Vale.
Playoff hopefuls Vale were closest to breaking the deadlock in the 10th minute when Mark Cullen’s header from David Worrall’s cross rebounded off the bar with goalkeeper Owen Evans beaten.
Referee Scott Duncan pointed to the penalty spot in the 42nd minute after a challenge from ex-Vale defender Charlie Raglan on Mitch Clark.
But after consulting with his assistant, he overturned the decision and the away side had to settle for a corner.
Cheltenham had threatened in the 11th minute when Alfie May lifted the ball over Scott Brown, but Leon Legge cleared off the line with Reuben Reid waiting to pounce.
Vale looked the more likely winners in the second half with Evans saving low to his left from Cullen after David Amoo’s centre and Amoo went close himself in the 64th minute, firing just wide after Tom Conlon’s pass.
John Askey’s men had another penalty appeal turned down after an hour when Conlon was challenged in the box.