The battle of the top two started with Kestrels moving ahead 5-0, but the leaders found their form and went 10-5 ahead.
Kestrels fought back and were just one shot behind going into the last end where Otters anxiously held on to earn a vital 13-11 win.
Both teams had won their earlier games, Otters defeating Mudlarks 13-8, and Kestrels seeing off Two Plus One 13-5.
Otters moved three points clear, but Kestrels do have a game in hand.
Wasps moved moved into third place, four points back, after thumping Dreamers 23-4, while Matelots slipped to fourth after losing 12-10 to Meridian.
The result moved the winners off the bottom of the table at the expense of Dreamers who had a bad week as they also lost 21-6 to Wishfuls.
Mudlarks are clear in fifth place after winning 13-9 against Scorpions.
* Malcolm Pearce and Mike Norton held on to their one-point advantage at the top of the Australian Pairs League.
They had to survive a nervous finish which saw them hang on for a 13-10 win against Linda and Martin Oldfield.
Jenny and Terry Cornwall remained in second place after beating Yvonne Cooper and John Clayton 17-7.
Only two points separate the next five pairs.
* There was only one game in Division Two where leaders Richard Tyrell and Pete Neve saw their advantage cut to three points after being beaten 18-15 by Anne Malcolm and Charlie Briggs who moved into second spot as a result.