Liverpool Lizards and Cheltenham were crowned the British Water Polo League Super 5s champions for 2015 after securing the titles at the final weekend of fixtures.
Liverpool had dominated the women's top flight this season, winning all seven games during the regular season, then their first seven games of the post-season Super 5s competition.
And they completed their perfect season with a 10-5 defeat of City of Coventry in Guildford this weekend with Fiona McCann scoring four of the winners' goals.
GB internationals Rosie Morris, Kathryn Fowler, Hazel Musgrove, Katie Hesketh and Rachel Drabble were also involved for the Lizards.
City of Manchester took the runners-up spot with a 10-5 defeat of last season's Super 5s champions London Otter.
The men's title came down to the wire with regular season winners Lancaster and Cheltenham taking on each other in the last game of the Super 5s with the victors to be crowned champions.
It was a hotly-contested final game but a late goal from Adam Legge gave Cheltenham - who won the British Water Polo Championships last season - a 14-13 victory.