Burnley had a great chance to take the lead on 16 minutes when Vokes chased down a back pass to force an error, before crossing to Dean Marney. However, some great defending from Danny Ings denied the chance.
Three minutes later, the away side did take the lead when Vokes poked home from the near post.
© PA Photos
James Henry came close to equalising on 27 minutes, firing just over from outside the area.
Vokes almost added a second on 36 minutes from Marney's cross, but his header went just over the bar.