Australian Charli Knott continued to impress with bat and ball as Southern Vipers secured the first victory of their defence of the Rachael Heyhoe Flint Trophy. For the second game in a row, 21-year-old Knott picked up two wickets with her offspin but upgraded the 41 she scored against South East Stars into an unbeaten 58 to set up a seven-wicket victory over Central Sparks. Katie George had saved Sparks from a collapse with a classy 52 to give her side 151 to defend. But Ella McCaughan's patient 43, Maia Bouchier's elegant 43 and Knott's in-control innings gave Vipers an uncomplicated bonus point win. Vipers only had one fast bowler in their attack, while Sparks were fully stocked with pace - but it was the hosts that got a flyer with the ball. Sparks were 31 for 4 and then 84 for 7, after being stuck in, as the Vipers kept taking wickets and building pressure. Eve Jones was the first to depart as she fatally took on Bouchier's arm at mid-off in the sixth over, before Knott pounced in her first over when Davina Perrin chipped to point. Also swooping at the picturesque Wormsley was a family of red kites, who stole an orange from Sparks' Hannah Baker and a banana off Vipers assistant coach James Hibbard. Abbey Freeborn was bowled by Linsey Smith, as the visitors only reached 27 in the first 10-over powerplay, before the left-arm spinner tclung on when Ami Campbell thumped back at her. Smith would end up with 2 for 20, with four maidens - the most economical Vipers bowling figures. Chloe Brewer had driven nicely and looked in good nick for her 23 before she tamely drove to Emily Windsor at cover, before Emily Arlott missed a Georgia Adams arm ball. Issy Wong picked out mid-off, but just as Sparks looked at a worrying sub-100 score, George and Ria Fackrell added 77. George, who had picked up five penalty runs after being hit with the ball by Charlie Dean, was in complete control throughout her innings - keeping things ticking on the leg side and using the off side for more expansive shots. She reached her third Rachael Heyhoe Flint Trophy half-century in 98 balls, Fackrell accompanying her with 39 to reach a more defendable total. But George fell the ball after raising her bat as she picked out long-on, with Fackrell run out in the last over as Sparks set 173 to win. In reply, Bouchier carried over her form from England's tour of New Zealand - where she scored 293 runs in eight innings - with boundaries galore in a glorious 32-ball 33 before she was adjudged lbw.