The wing had five before the interval, and with Jack Digby, Joe Luca Smith and Charlie Piper also dotting down, plus seven Ed Morgan conversions, it was 54-0.
Park extended their lead with another Digby seven-pointer, but Lions got off the mark as Theo Mannion added to a Max Humphreys effort.
But Max Fraine bagged a brace, Benji Marfo went over and Mehson added two more to complete the rout.
Big wins for Albion and Club
Second-placed Plymouth Albion confirmed at least a play-off spot with a 68-24 home success against struggling Sedgley Park.
Ryan Lamb’s men raced into a 40-o lead with Bobby Wigginton (two), Rhys Williams, Ben Raivalita, Jack Oulton and Iwan Jenkins all touching down.
The latter slotted five kicks before the visitors reduced the arrears with tries from Rhys Henderson and Adam Mallinson, Greg Smith on target after the first.
But Albion sewed the contest up with Oulton, Oscar Stewart, Morgan Stone and Josh MacAndrew over, Jenkins with another four conversions.
Tigers, though, grabbed two injury-time tries through Jack Ellam and Danny Rylance to snatch what could yet be a vital bonus-point.
Blackheath are also set for at least a play-off and ended Sale’s hopes with a 40-19 home win.
The visitors took an early lead as James Robbins added to a Huw Davies try, but five-pointers from Luke Pollock, Tom Hughes and Billy Harding – with a league record-breaking 43rd of the season – gave Club control.
Davies doubled up to reduce the gap, but Pollock made it 20-12 at half-time.
Ed Scragg grabbed Club’s fifth before Nathan Langdon and Robins made it a six-point game.
But Blackheath finished things with Fin O’Sullivan and Tom Emery crossing the whitewash before Sam Morley finally added five points with the boot.
Dazzling Dings claim Stortford thriller
Dings Crusaders gave their survival hopes a massive boost with a 40-34 home win against Bishop’s Stortford.
The Bristol side raced into a 26-0 lead with Tomos Gwilliam, Joe Jenkins, Sam Scott and Harry Rowson crossing, George Boulton on target three times.
Stortford hit back before the break as Chris Bolton added to his own try before Ioan Parry went over.
A Sam Cantwell seven-pointer gave Dings breathing space before Bishop’s rallied with a Jake Morris brace and a converted Frazier Kiff effort.
But Ethan Surrey finished for Crusaders, Boulton on target, meaning Tom Mills’ late try was merely a consolation.
Leeds leave it late, TJs take down Clifton
Leeds Tykes grabbed a last-gasp 25-24 victory at Birmingham Moseley as they all but secured Level Three status for 2026/27.
The hosts led 12-0 after Tighe Maxwell-Whiteley converted an Elliott Creed try, Ben Pogson then over from a maul.
Leeds hit back through Charlie Venables and the boot of Ed Crossland, the fly-half with a conversion and penalty.
Ollie Stedman and Lucas Walsh exchanged seven-pointers before Crossland’s second penalty edged Leeds in front.
Pogson looked like he would have the decisive say, only for Ben Bailey to prove the match-winner in the final minute.
Defeat leaves Moseley two points above Clifton, who they visit this Saturday, the Bristolians having lost 33-24 at Tonbridge Juddians.
Tries from Will Holling, Shadyn Osgood and Curtis Barnes, plus two Connor Lloyd conversions, pushed TJs 19-0 up.
Freddie Myatt touched down for Clifton, but seven-pointers either side of the break from Vinny Everitt and Lewis Gjaltema had the hosts in complete control.
Clifton salvaged a try bonus-point through Christian Packer, Zak Hamid and Jack Bennett, but it wasn’t enough.
Tom Quinlan kicked two conversions for the away side.
The first chance to make amends on Saturday against visitors Rosslyn Park (3pm). For tickets, click here
