Slocombe was called into action again inside the opening 10 minutes, but this time it was a more comfortable stop for the keeper as he denied Eoin Morgan's strike.
Doyle had a better chance soon after having been played through on goal by Gary Roberts, drawing another good save despite stumbling at a vital moment.
Gary McSheffrey looked to alleviate the pressure in style with a 45-yard lobbed effort that Tommy Lee had to be alert to, but the hosts were soon back on the front foot and tested Slocombe again through Armand Gnanduillet.
Lyle Taylor threatened to give the visitors the lead just before the half-hour mark when he had space to shoot, but his lob was disappointing and went a long way over the bar.
Neither side could find the breakthrough in the closing stages of the half as they went into the break all square.