IT was a big day for New Brighton who clinched the South Lancashire / Cheshire One title with three matches remaining.
Birkenhead picked up a losing bonus point but now trail their Clatterbridge rivals by four points.
A key decision in the third quarter had a major bearing on the outcome with Park's Lawrence Cowan dismissed for alleged foul play which was claimed to be retaliation.
At the time Park were ahead 15- 12 but Wirral took advantage of the situation to score a crucial third try via Craig Harvey with their opponents down to thirteen men at the time through a yellow card.
The visitors were against the elements in the opening period but managed two forward tries via Stu Brown plus an unlikely touchline conversion by Dave Hall.
Alistair Baker and James Annetts ran in excellent touch downs for Wirral with a Harvey goal making it 12-12 at the half way stage.
A Hall penalty nudged Birkenhead in front before the Harvey try and then a penalty by the same player saw Wirral to a double after a tense last quarter.
The title and automatic promotion is still in the balance but really it is in Wirral's hands.
They have enjoyed a terrific season to date and can make sure by winning their last three outings which is very much on the cards.
That would leave Birkenhead facing a play-off, probably at home, for the second promotion spot.
Caldy travelled to Birmingham Solihull in National Two North.
They found the Midlands outfit to strong and fell to their fifteenth reverse 15-35 but are safely placed towards mid table.
New Brighton were too good for Wigan at Hartsfield and finished 32-10 winners. Win number 22 put them 18 points clear of nearest rivals Northwich.
Wigan did not surrender easily but Joe Silcock was the first to breach their defence with the conversion and two penalties by Anthony Birley earning the Blues a 13-3 interval lead.
Kati Tuipulotu helped himself to a brace of touch downs later with Joe Cardus also getting in on the try act.
Influential fly-half Birley added two more goals and it was time to celebrate.
Brighton can now enjoy the last stages of the campaign and the Cheshire Vase final before preparing for next season in North One West.
Anselmians are third in the table after edging the verdict 26-22 in the Isle of Man against Douglas.
Hoylake went down 22-33 against West Park at Melrose Avenue but now have a big chance of escaping the drop with second bottom Tyldesley having been docked a vital ten points.
Port Sunlight came away 37-5 to the good from Dukinfield in Division Two but it was another demanding day for winless Wallasey who were beaten 0-53 at Ormskirk.
In Division Three Ellesmere Port beat Oxton Parkonians 14-10 and share top place in the table with Trentham.
Prenton came away 45-21 to the good from Capenhurst whilst Oldershaw played out a 19-19 draw against Congleton at Belvidere.
Caldy have a tough but attractive home clash with table toppers Macclesfield this Saturday.
Birkenhead Park should be too strong for lowly Altrincham Kersal at the Upper Park whilst Wirral take the road to Warrington.
There is an Anselmians v Hoylake derby with New Brighton away at Ashton on Mersey who are facing relegation.
Other fixtures include Port Sunlight at Bowdon, Wallasey v Orrell, Ellesmere Port at Congleton, Oxton Parkonians v Helsby and a Prenton v Oldershaw derby.