Pier were stunned into action after just five minutes when Cameron Dobson opened the scoring for Hunmanby.
Within a minute Martin Cooper had restored parity, before a quick-fire double from Billy Logan pushed Pier clear.
Ryan Baldry kept Hunmanby in the game when he scored their second before the break, but Pier marched 5-2 clear when Logan wrapped up his hat-trick and Cooper bent home his second with a superb free-kick.
Hunmanby striker James Pinder trimmed the lead back to two, but Pier defender James Wardle waltzed forward in the latter stages and finished with a curling effort to seal the victory.
Cooper and Chris Nelson excelled for the victors, while Dobson and Pinder were a constant threat for Hunmanby.
Newlands Park's title dreams were kept alive by a 1-0 victory against Filey Town.
After an end-to-end encounter, Newlands struck the killer blow in the 88th minute when Carl Hepples tapped home after a swift counter-attack.
Gary Hepples and Brad Rowley the the stars of the show for Park.
Rosette and Itis Itis Rovers shared the spoils after a 4-4 draw in Division Three.
Martin Russell back-headed Rosette into the lead, before Alex Wray and Tommy Blackburn put them firmly into the driving seat.
A pair of defensive errors gave Itis Itis a sniff as they pulled it back to 3-2 at the interval.
Rovers then levelled the proceedings, before a 25-yard strike from star man Joe Ferrie forced Rosette's noses back in front.
Once again Itis Itis drew level, but in the dying embers Jack Worthy was presented with the perfect chance to seal all three points for Rosette, but he fluffed his lines.
Scalby Reserves pulled off something of a shock result when they beat FC Sherburn 4-1.
Scalby took the lead after 10 minutes, George Wilson firing in from close range after a scramble in the box.
Sherburn keeper Andy Slaughter kept his side in it with a couple of good saves and the hosts nearly equalised after 35 minutes but were denied by a fine goal-line clearance from Nick David.
Scalby hit the post three times in the space of 10 minutes at the start of the second period before substitute Sam Swift finished off Tommy Day's cross from the left after an hour.
Another substitute,Terry Day made it 3-0 and although Sherburn got a goal back when Rhys Howell deflected a free-kick past his own keeper in the 88th minute.
Terry Day's second rounded things off for Scalby in added time.