Mermaid pulled away from Portsmouth Men’s Summer League division C’s relegation places with a 5-4 triumph over Raven.
Paul Marsh and Sean Spillett put Raven 2-1 up with legs either side of a win for Matthew Boulton.
Mermaid went ahead for the first time as Jamie Andrews and Kelvin Fletcher posted wins but Lee Simmons soon restored parity.
Arnie Le Rouge and James Woolley won the next two ties to give Mermiad an unassailable lead – leaving Bob Steel to take a Raven consolation.
Harvest Home B dropped to third in division D after Pembroke came from behind to beat them 5-4.
Robert Jones and John Bailey got Pembroke off to a fine start but they were soon trailing as Paul Manganzini, Charlie Hymers and Paul Sibson were all on the mark for Harvest.
Pembroke’s Danny Jones made it 3-3 before Peter Webb put Harvest within a leg of victory.
But Pembroke snatched victory from the jaws of defeat as Steve Brett and James Iles won the final ties.
Admiral Drake B maintained their advantage at the top of division A with a 7-2 win over Lord Chichester B.
Drake wasted no time in guaranteeing themselves the points as Mike Symes, Bill Sturgess, Barry Stevens, Danny Smith and Gary Collis put them 5-0 up. Sturgess threw an 18-darter and Collis hit a 180 and 100 finish.
Kevin Gilchrist got Chichester off the mark with a pair of 18-dart legs and a 180, while his opponent John Bradshaw also scored a maximum.
Drake’s James Brooker took the sixth in style with 13 and 18-dart legs and scores of 174 and 180.
And his team-mate Charlie Jackson followed it up with a 14-darter as he won his set.
John Madgwick Jnr won the last set as a consolation for Chichester.
Lord Chichester A beat Thatchers B 5-4 to leapfrog them in division B and move out of the bottom two.
Mark Brooks Jnr opened Thatchers’ account but Chichester took control with Terry Dugan, Curt Laming, Bob Ketchen, Austin Egan and Pat Reed propelling them to victory.
Matt Lock, Sunny Legg and Danny Legg made the scoreline more respectable for Thatchers.
Neil Hewson (Mr Pickwick A) threw a 15-dart leg and 180, while Anthony Quintavalle (Jolly Taxpayer C) registered a pair of 18-darters.
Steve Filby (Jolly Taxpayer C), Liam Jafkins (Mr Pickwick B) and Liam McGuire (Mr Pickwick A) also finished legs in 18, with Jafkins and McGuire hitting 180s.
Alistair Perkins (Mr Pickwick A) hit bullseye for a 130 game-shot, while Robert Houghton (Duke of Devonshire B) hit a 109 finish.
Chris Harradine (Rose in June B), Phil Mercer (Harvest Home A) and Frankie Howard (Newcome Arms A) checked out on 104, 103 and 100 respectively.
Colin Prout (Stag A), Andy Newcombe (Jolly Taxpayer C), David Clarke (Jolly Taxpayer B) and Vic Smith (Mr Pickwick A) all fired in maximums and Tom Money (Jolly Taxpayer B) scored 171.