The Berkshire men did things the hard way having slipped 12-0 behind inside 10 minutes, Jack Digby and Luke Mehson crossing for the hosts.
But Rams responded supremely, Mike Cooke adding two conversions after Paddy Harris, Oli Rhoads and Rowan Grundy touched down in a helter-skelter opening 23 minutes which saw the visitors lead 19-12.
Rosslyn were back in front before the break, though Benji Marfo and Mehson over.
Connor Stapley’s extraordinary 60-metre interception dash, added to by Cooke, had Rams back in front early in the second half, and a seven-pointer from man-of-the-match Zach Clow nudged Rams 33-22 ahead.
Park came again through George Orchard and a Steffan James conversion, only for their opponents to close thing out as debutant Henry Bartlett dotted down late on, Cooke’s brilliant touchline kick sealing the deal.
Coach not surprised by early Christmas cracker
Reflecting on a marvellous win, Seb said: “It was a very good performance.
“Rosslyn Park been playing some great rugby, look dangerous as a side and I’ve been very impressed with what they’ve been doing.
“I said before I thought it would be a great game and I’m not surprised by what both sets of players produced – it was all-action from the word go with loads of tries.
“Everyone got to see a brilliant game, and I’ve got to give great credit to the lads.
“There was a brief spell in the second half where we were transpiring to bring them back into the game with a few moments of questionable game management, yet we got it together.
“It’s not been the easiest few weeks, but the guys were superb and we always felt with this squad they could produce this kind of thing.
“It shows we’re on the right trajectory.”
‘Zach was fantastic’
The head coach had spoken pre-match about the need for a fast start and to stop free-scoring Mehson, and he joked: “It was better than last year – we were only 12-0 down rather than 19-0!
“Early on we dropped off a couple of tackles and Luke’s a top player – it’s almost impossible to keep someone like that quiet for 80 minutes.
“But our defence in the second half was very good and it speaks to the work of the effort the lads are putting with Phil (Hoy, head of strength and conditioning) that we could come here and stay in the game for the full 80 minutes.”
Star of the show was the irrepressible Clow, with Seb adding: “He was fantastic. He looked dangerous every time he got on the ball, exploited the wide channels early on very well and his options of when to kick were also excellent.
“He’s a great player and his attitude is ever-improving – he’s such a character in the group and huge credit to him.”
Seb focused on team’s development
The victory in London was Rams’ first against a top-six side this season, but Seb played down its significance and said: “I’m not really interested by that – I respect this league immensely and it doesn’t matter who we’re playing because they are all good teams.
“I’m only interested in how we’re developing and performing.”
And with magnificent visiting backing which at times made it feel like a home game, he ended: “Everyone enjoys the train trip and away days are good fun.
“I saw someone in the morning on a dog walk who said he’d see me there, and it’s so nice for people to travel and support the team.
“We want to put on a product people can get behind and see an exciting team play, and we did that, so I’m pleased.”
Rams are again on the road at Bristol-based Dings Crusaders for their final game of 2025 next Saturday (3pm).
