Clarke Willmott & Clarke has poached two partners from south-west sports law practice Alsters, forcing the closure of the six-partner firm.
Clarke Willmott & Clarke plans to go head-to-head against Bristol rival Osborne Clarke in the battle for high-profile sports law work.
Alsters, regarded as the top firm in sports law in the South West, also specialised in commercial property. It ceased to exist on Friday and the partners have gone to other firms.
Once senior partner David Powell and commercial property lawyer Jamie Kidd had accepted the offers from Clarke Willmott & Clarke, the remaining members decided to break up the firm.
Eight fee earners have followed Powell and Kidd over to Clarke Willmott & Clarke.
Clarke Wilmott & Clarke managing partner David Sedgwick says that without Powell and Kidd, Alsters could not survive.
He says: "We approached David Powell as we have got the biggest planning practice in the West Country but we wanted to strengthen our commercial property department. We thought that David Powell's property practice, particularly his house building contacts, would be useful.
"Without David and Jamie the practice could not continue. Unfortunately the rest of the practice does not fit with what we are trying to do."
Powell counts the Professional Rugby Players Association, the England Rugby team, rugby players Kyran Bracken and Jeremy Guscott and golfer Gary Wolstenholme among his clients.
Powell says: "We had reached the point where our continuing growth in the areas of commercial property and sports law could only go forward as part of a much bigger firm."
A former Alsters partner says that the partners decided it would be very difficult to continue having lost their senior partner and that reluctantly the partnership would be dissolved.
Company law partner Philip Albery is believed to be moving in-house for two clients. Litigation partner Peter McKnight joins litigation firm David Gist and the destination of the remaining partners is unknown.
Alsters was founded in its present form in 1984, although it has a history dating back to before the Second World War.