A Joe Green penalty had the Dogs in front before Park hit back, Charlie Piper and Steffan James touching down with the first converted.
Sale then moved ahead thanks to a second Green penalty and five-pointers from Josh Brown and Tom Walsh, Rosslyn 17-16 up at the break thanks to a Charlie Walker try.
Alfie Longstaff crossed and Green landed another penalty to have their side seven clear midway through the final quarter, but back three aces Luke Mehson and Benji Marfo had the final word.
Titans and Albion made to work hard
Rotherham Titans came-from-behind to avoid a second straight loss, beating visitors Tonbridge Juddians 38-28.
The Kent men went in front as Connor Lloyd converted an Archie White try, Titans taking the lead as Morgan Veness and Jackson Barling touched down, Corben Ollivent adding to the latter.
Yet TJs were up 21-12 at half-time, Lloyd and Tom Nicoll over with seven-pointers.
John Okafor touched down for Roth, but their opponents moved further clear as Lloyd again landed after Curtis Barnes crossed.
However, Barling, Isaac Shaw and Okafor all grabbed converted draws to keep the pressure on Park.
Plymouth Albion are back up to third after beating Birmingham Moseley 36-21 under The Brickfields floodlights.
In front of a superb crowd of 2,027 it was Albion who struck first Frankie Dart adding to tries from Oscar Stewart and Bobby Wigginton.
Moseley earned a penalty try to halve the deficit, the two teams then sharing seven-pointers from Shea Cornish – Dart on target – and Tighe Maxwell-Whiteley.
A Plymouth penalty was replied to via Ethan Priest and Maxwell-Whiteley for 24-21, but Wigginton and Cornish doubled up to seal the deal.
Sedge hold off Dings, Lions roar again
Sedgley Park are seventh after they beat visitors Dings Crusaders 29-22.
Early scores from Alex Wills and Adam Mallinson, plus an Oli Glasse conversion, made it 12-0 before Sam Cantwell got the Bristolians on the board.
Rhys Henderson and Glasse made it 19-5 by half-time, but Brian Ncube and Lewis O’Grady hit back.
Glasse added to Mallinson’s second, but Cantwell doubled up and Sol Taufa scored Dings’ third before a last-minute Glasse penalty.
Leicester Lions made it back-to-back wins to leapfrog Leeds Tykes following a 24-19 away win.
The hosts were 16-0 up thanks to Ewan Laughton’s try and 11 points from the boot of Seraamia Turagabeci, Lions off the mark in the final minute of the first half through an Ollie Crane effort.
Crane grabbed a quick-fire second, this time added to by Luke Bouchier, but another Turagabeci penalty made it 19-12.
Yet two more tries from Brad McKenna secured a full five-point haul for Lions.
Clifton cut loose
Bishop’s Stortford slipped to bottom after a 55-29 setback at Clifton.
Tom Quinlan converted an early Matt Jones for the hosts, only for Stortford to lead 19-7 after Alex Gilham, Toby Hill and Finn Keylock touched down, the latter with two conversions.
A Tom Anderson double, one converted, level things before Keylock’s penalty nudged Bishop’s back in front by the break.
Clifton seized control, however, Mitchell Spencer, Ollie Harris, Jay Evans pushing them 38-22 up.
Keylock landed after Isaac Bell secured a try-bonus for Stortford, but Cliton moved past their half century with Ollie Stirling, Toby Hutchinson and Brad Talbot all over the whitewash.
Rams were beaten for the first time at Old Bath Road this term, Blackheath taking advantage of an early red card to win 26-7.
