A Luke Mehson double plus tries from Freddie Vaughan and Charlie Walker, all converted by Steffan James, put the hosts 28-0 up before Ollie Glasse added to a Ben Gregory for Tigers.
Rosslyn replied unbelievably after the break as Walker completed a hat-trick and Ed Volley also went over, James’ boot making it 49-7 midway through the third quarter.
A converted Billy Addy effort doubled Sedge’s tally, but Mehson finished for a treble and Volley then grabbed a second as James maintained perfection from the tee.
Gregory went over for a consolation before Jake Cleet ended the scoring for the new leaders.
Titans and Plymouth shocked
Previously unbeaten Rotherham Titans were stunned 50-31 at Dings Crusaders.
Will Thompson, Archie Stanley and Tom Knight all touched down inside 15 minutes for the hosts, Lewis O’Grady with two conversions before Issac Shaw got Roth on the board.
But further tries from Evan Morris and Harry Rowson, the latter converted, made it 31-5 at half-time.
Titans struck first after the break as Lloyd Hayes added to a Jackson Barling effort, only for Roswon and O’Grady to reply.
A Morgan Veness seven-pointer reduced the arrears before Morris bagged a second, O’Grady landing for 45-19.
Rotherham salvaged a try bonus through Harry Newborn, Hayes on target, but Dings reached 50 through Kenzie Jenkins before Mitchell Lacey-Babalola’s late consolation.
Plymouth Albion dropped to fourth after a 35-25 reverse at Tonbridge Juddians.
The hosts drew first blood as Connor Lloyd added to a George Merrick try, Harry Wilkinson hitting back for Plymouth.
Lloyd landed again after former Ram Vince Everitt dotted down, Wilkinson doubling up before Jack Oulton nudged Albion in front.
TJs led at the break, though, Lloyd converting his own try for 21-15 before Ben Moa and Oscar Beckerleg had the visitors four clear 10 minutes into the second half.
Lloyd remained perfect from the tee after Luke Boon and Curtis Barnes crossed midway through the final quarter, however, securing the upset.
Club, Sale also upset
Birmingham Moseley shocked visitors Blackheath 32-19 for just a second win of the season.
Jordan Burns gave Club an early lead, Kyle McGhie converting, before Ben Pogson replied for Moseley.
After Tuoyo Egodo went over hooker Pogson doubled up, Dan Brough securing the bonus-point as two Tighe Maxwell-Whiteley conversions made it 24-7 at the interval.
Blackheath got back into things with McGhie on target following a Billy Harding effort, Findlay Gilmour then over to cut the gap to five.
But Birmingham held their nerve, Egodo crossing before Tommy Taylor’s penalty finished things.
Leicester Lions claimed a sensational first win of the season with a 35-31 home success against Sale FC.
A Joe Green try put the visitors in front before Leicester replied through Freddie St John and George Pearson, both scores added to by Luke Bouchier.
Sale hit back as Will Davies converted Ciaran Parker’s try for 14-12 at the interval, the Dogs nipping in front as Mark Dixon touched down.
The lead switched hands twice more as Ollie Crane then Alfie Longstaff grabbed seven-pointers, Lions then moving clear as Bouchier made it five from five after he and Bronson Mellowes crossed the whitewash.
Ralph McEachran gave Sale hope, but his late try proved too little, too late.
Tykes make it two wins from two
Leeds Tykes climbed out of the drop zone as they made it back-to-back victories with a thrilling 46-36 triumph at Bishop’s Stortford.
Seb Krippner put the visitors in front, Ed Crossland with the extras, before Bishop’s levelled through Harrison Langworthy and Chris Bolton.
Crossland kicked a penalty, but the Hertfordshire hosts edged ahead as Bolton struck again after Jake Morris touched down.
Leeds, however, then hit the front through another Crossland penalty and seven-pointers from Aarin Yorke and Henry MacNab.
Alex Rayment reduced the arrears to 27-19 10 minutes into the second half, but Leeds pulled clear as Ewan Laughton, Reuben Parsons and Ben Dixon dotted down, Crossland twice more on target.
And while Stortford launched a spectacular last 10-minute rally – Ryan Davies, Cameron Meechan and Tristan Smith all scoring as Dan Cole converted the latter – it was only enough for a bonus-point.
Rams, meanwhile, moved up to third with a hard-fought 21-14 victory at Clifton.
Next up at Old Bath Road is Blackheath on Saturday. For tickets, click here
