Alan Irvine waited three games for his first win as manager but when it came it came in emphatic style as a second half showing put paid to the Tigers' unbeaten run.
The North End boss asked for patience ahead of the game and that's exactly what was needed after an efficient first-half finished goalless but that was followed by a dynamic second half display. For once the Lilywhites were afforded some luck when Caleb Folan smashed a first-half shot against the post but that was Hull City's only real chance of the game and once Agyemang sprinted clear on 58 minutes to slam home the opener there was no looking back for North End.
If the sigh of relief was audible after Agyemang's first there were screams of delight when Whaley doubled the advantage after a brilliantly worked move ten minutes later and Alan Irvine showed that he is astute at substitutions when he sent on Mellor and Lewis Neil late in the game, the duo combined brilliantly to seal the win with Neal sliding in to push home Mellor's cross.
It was a reward for patience for all concerned and a crucial victory ahead of the massive derby game against Blackpool on Saturday.
The Tigers had a chance as early as the fourth minute when Richard Garcia whipped in a corner from the right and Youl Mawene's header only reached the penalty spot where Dean Marney was waiting but he flashed his shot high over the bar.
Preston almost grabbed the first goal of the game in fortunate circumstances when Boaz Myhill rolled a ball out to his centre-half Wayne Brown, the Hull defender turned to play the ball out but he hadn't counted on Callum Davidson closing him down so quickly, the Scottish midfielder was right in his face and he deflected Brown's shot right towards goal, Myhill was beaten but the ball fortunately went wide for the Tigers.
Sedgwick had a great opportunity in the 23rd minute. Simon Whaley had found plenty of space in the box after Paul McKenna had played a cross-field ball to the left. Whaley cut inside onto his right and squared a ball across goal to Ormerod who just nudged it into the path of Sedgwick, but it was on his left foot and was sliced over the bar.
Hull City came straight back at PNE though and they maybe should have taken the lead, Caleb Folan had bundled his way into the box before hitting a powerful drive to Lonergan's near post, it clattered off the woodwork and away, a piece of good fortune at last for the Lilywhites.
An early change for the Lilywhites saw Preston take off Brett Ormerod for Paul Gallagher.
Michael Turner was the first booking of the game in the 37th minute of the match when he was exposed by Whaley's pace and was led into a lunging challenge which had the crowd off their seat.
Preston North End started the second half brightly and had a couple of decent chances on 50 minutes, the first when Agyemang got well clear down the right and his low cross into the six yard box looked destined for Gallagher's boot but for a late intervention from Wayne Brown for a corner. From that corner-kick Davidson and Whaley worked a quick one and it was Whaley who dipped in a cross to the near post that span across the face of goal, it was begging to be put away.
Andy Lonergan was called into action in the 54th minute when Frazer Campbell did well to prevent the ball from going behind for a goal kick and his cut back landed at the feet of McPhee who drilled a shot at goal, Lonners managed to divert the powerful effort behind for a corner.
North End went in front on 58 minutes and it was a simple but brilliantly worked goal. Sean St. Ledger picked up the ball in defence and knocked it infield to McKenna who just nudged the ball forward to Gallagher, the Scottish forward took his time and played the perfect ball into space for Agyemang to run on to. The pacey striker was clear and set off towards goal, taking one or two touches before slamming the ball across goal and into the back of the net.
The Tigers made a double substitution after North End's goal with Dean Windass and Jay Jay Okocha coming to add plenty of experience to the Hull side, Folan and McPhee were the players to go off. The Yorkshire side made a third and final change when David Livermore came on for Frazer Campbell.
The Lilywhites went two up on 68 minutes when Simon Whaley finished off a superb North End counter-attack. It all came after Okocha was caught in possession deep inside his own half, it was Sedgwick who did the pick pocketing and he played the ball into the path of McKenna on the right, the skipper looked up and whipped a ball across goal, it seemed like the PNE players had all left it for each other but they hadn't accounted for Simon Whaley arriving at the far post to slam a shot towards goal, it found the back of the net courtesy of a Sam Ricketts boot.
Dean Windass could have reduced the arrears on 73 minutes when he flashed a volley across goal from outside of the box, it had Lonergan scrambling across goal but it flew just wide and then Windass had another chance moments later when Marney nodded a ball into the path of the ageing striker but he took a complete airshot at the ball.
Preston made a double substitution late in the game and it was an inspired move by Alan Irvine. Neil Mellor and Lewis Neal came on for goalscorers Simon Whaley and Patrick Agyemang and the super-subs combined to make the game safe for PNE. Mellor picked up the ball with plenty of space to run into on the right and he took on his man and beat him before delivering the perfect ball into the six-yard box. It was Lewis Neal who bravely slid in to fire the ball into the top of the net to the delight of the Deepdale faithful.
