Victory was a relief for the London side after their defeat at the hands of City of Coventry on day one. Coventry completed a hat-trick of weekend win, beating City of Leeds 15-9 and City of Sheffield 9-3.
Otter also picked up maximum points against Sheffield (12-7) and Leeds (11-7) and so both they and Coventry are already through to the Super 5s. City of Manchester and Liverpool Lizards will look to follow suit when northern clubs play matches at Liverpool next weekend.
In Division Two, also at Gloucester, West London Penguin made it six wins out of six, beating Liverpool Water Beatles 12-3, Welsh Wanderers 13-7 and second-placed Mid Sussex Marlins 10-7.
Welsh Wanderers and the Water Beatles drew 6-6. Liverpool salvaged a point a minute from the end with a goal by one of the youngest players in the League - 13-year-old Emily Pyper.