Grayson made several changes fromt he weekend's poor display against Oldham. Whilst changes were always going to be made the line up surprised some with Hughill being supported by Hayhurst and Laird.
The Preston boss had Saturday's game in mind when picking his team although he assessed that there were positives to take from the game by those who played.
The first half was goalless before a speight of goals in a 15 minute period in the seond half. Lee Tomlin put the home side in front from a free kick before Hughill soon equalised.
A Clarke own goal followed by Tomlin's second sealed a victory for Middlesborough. Preston now move on to a tricky home test against promotion favourites Sheff Utd on Saturday at Deepdale.