A fine solo goal from Neil Thomas put Pier ahead at the break, and although Kile Fields hit the post for Park Thomas then turned creator after the interval supplying the cross for Paul Provins to wrap up the win.
Hunmanby United moved into third place after a 4-0 home win against second-placed Edgehill.
United dominated from the kick-off and went ahead through a fine strike from James Pinder from the edge of the area.
The hosts doubled their lead when Leigh Franks shot home from 10 yards after a Ryan Baldry throw, and Oli Milner’s fine finish wrapped up the game before half-time.
Five minutes from time United completed the scoring, Ryan Baldry broke through after a pass from his brother Dan and then shot at goal, his effort hitting the post and coming back out for Jon Hyde to slot in.
The while United team shared the man-of-the-match award, who completed a league double over Edgehill for the first time in at least a decade.
Seamer Sports claimed a 5-3 home win in a bizarre home game against a depleted Cayton Corinthians side.
A Harry Sleep double put the visitors, who started with a bare 11, 2-0 up at the interval but four Cayton players left at half-time to ensure that the reserves had a full team for their home game with Filey Town Reserves in Division Two.
Seamer took full advantage of this and roared into a 3-2 lead, and although Mark Davison levelled, the hosts struck another two goals to seal the win.
Gaz Lawton, Ben Mason, Ali Caw, Joe Gallagher and Jamie Hartley netted for Paddy Parke’s side, Hartley scoring the pick of the bunch with a fine header.
A weakened Filey Town side slipped to a 4-0 home win against Whitby Fishermen.
Division Two champions Newlands Park Reserves battled back from 3-1 down to earn a 7-4 home win against Duchess.
Jason Prosser put Newlands ahead, but Matty Hobson’s cross caused a home player to put the ball into his own net.
An Ian Jenkinson double after the interval put Paul McBean’s troops in charge, but a Stew Bates brace levelled the scores and Hughie Brown’s effort put the champs in front again.
Bates then completed his hat-trick to make it 5-3 and Prosser’s second sealed the win, despite James Hughes netting the away side’s fourth.
Drew McCoubrey scored the seventh for Newlands, whose man of the match was central midfielder Rob Bowman.
McBean hailed the midfield trio of Chris Watson, Luke Midgley and Tim Jackson.
Seamer Reserves cruised to a 5-1 home win against Scalby.
Arran Wright, Tom Adams, Dan Jewitt, Daz Hastie and Luke Tinker netted for Seamer, Shaun Scales replying for Scalby.
Lee Tate was named as the Seamer man of the match.
Filey Town Reserves won 3-1 at Cayton Corinthians Reserves.
Martyn Jenkinson’s 18-yard strike flew into the top corner to put Town ahead at the break and although Jamie Whitelaw’s goal levelled the scores, man of the match Joe Gage surged upfield from centre-back to notch the winner 10 minutes from time.
Dan Louth was named as the man of the match for a strong display in central midfield for Cayton.