Last season's Scarborough Sunday League Division One runners-up Trafalgar suffered a shock 3-2 loss at home to Valley, despite having been 2-0 ahead.
Valley made a bright start and missed two clear chances from close-range in the early stages went narrowly wide.
Then a lapse of concentration from a corner let a depleted Trafalgar in just before the break.
The second half began with high Valley pressing but still being unable to find the finishing touch before Traf punished a lapse of concentration on the ball to double their lead.
Valley picked their heads up and kept battling then centre-back Josh Westmoreland scored a superb scissor kick into the top corner from a corner to bring hopes of a comeback before Jake Adams burst from centre-half to strike a 40-yard screamer into the top corner and level the scores 10 minutes before time.
Then in the dying seconds Michael Hernandez headed the ball into the bottom corner after a long spell of Valley pressure to win the game for the visitors.
Vallley boss Ben Kristensen said: "I would like to congratulate the lads for the massive effort and work rate displayed.
"Man of the match was Jake Adams for his commanding performance at centre-back and his incredible 40-yard screamer."
Defending champions Angel Athletic were also thankful for Robbie Scarborough's 85th-minute leveller in their 1-1 draw at Newlands.
Newlands opened the scoring on 65 minutes thanks to a great strike from Sam Turner, but Angel, who had hit the woodwork four times, grabbed a point late on thanks to Scarborough.
New Newlands boss Dan Sheader, who has taken most of his old Cask team from last season back to his old club, said: "Every single one of the lads played superbly, it was a brilliant performance.
"Special mention must go to our keeper Callum Myers though as he pulled off four amazing saves."
Angel's man of the match was centre-back Callum Gravestock.
West Pier dug deep for a 4-3 win at newcomers Cayton Corinthians.
Jordan Scott banged in two goals for Pier, with Jordan Scott and Dane Robinson also on target, with Brad Atkinson their man of the match.
Cayton went ahead early on through Tom Macdonald, then went 2-1 down before Callum O'Keefe levelled but Pier notched again before the break.
An error by Cayton defender Ste Molloy allowed Pier to go 4-2 ahead, and despite Shaun Dolan toe-poking home a third for Cayton it was too late to save them.
O'Keefe, on the left, wing, and central midfielder Rich Bissessur were the star men for Cayton.
Eastfield Athletic continued their fine start to the season with a 2-0 home win against Saints.
The hosts made the ideal start, Adam Martin notching after fine work from Jamie Hartley.
Chris Milburn added the second goal just after half-time, Hartley again claiming the assist.
Man of the match for the victors was Tom Hickin, who gave a commanding display at centre-back despite carrying a knee injury.
Right-back Ben Robinson was the star man for Saints.
Hosts Fylingdales and Castle Tavern shared the spoils after a 2-2 draw.
Simon Forde notched twice to put the villagers in charge at the interval.
Tavern battled back well after the break, with the predatory Paul Mills, on as a half-time sub, pouncing to net both for the visitors, who ended the game strongly.
The Tavern man of match was Konrad Sygitowicz with a great strong performance in centre midfield, while the star man for the hosts was Mike Coates.
Left-back Steve Chittenden also played well for Tavern and provided both assists.