Roy Keane claimed Ole Gunnar Solskjaer's 'gamble' on signing Edinson Cavani has paid off after his match-winning double fired Manchester United to a superb comeback win against Southampton. The Red Devils trailed 2-0 at half-time but Bruno Fernandes' finish before a late double from substitute Cavani saw United produce a stunning turnaround in a 3-2 victory at St Mary's. Edinson …