Thunder kept alive their slender hopes of Rachael Heyhoe Flint Trophy qualification with a comprehensive eight-wicket victory over Central Sparks at Worcester.The win was set up by the excellent bowling of left-armers Tara Norris (four for 18) and Sophie Morris (three for 31) as Sparks were bowled out for 144 in 42.4 overs. Only captain Eve Jones (38 from 62 balls) threatened to play a match-shaping innings for the home side in an error-strewn team batting display.Thunder then cruised to 147 for two with a whopping 21 overs to spare as third-wicket pair Emma Lamb (71 not out, 84 balls) and Katie Mack (52 not out, 69) added an unbroken 122 from 134 balls.The northerners’ win lifted them above their hosts in the table and maintained their interest in the qualification picture. Sparks, on the other hand, are left with little more than pride to play for in their remaining games.Thunder chose to bowl and inflicted serious early damage, abetted by the home batters’ reluctance to get on the front foot. Sparks stumbled to 52 for four after 13 overs with all the casualties bowled or lbw as they stayed back in the crease.Norris struck the first two blows, Chloe Brewer lbw and Abi Freeborn bowled leg stump. Left-arm spinner Sophie Morris delivered the next two, both bowled as Davina Perrin played down the wrong line and Courtney Webb was caught in two minds and saw her middle stump hit.Skipper Jones was the exception to the top-order indecision but perished in pursuit of her sixth four when she chipped Sophie Morris to mid on.Katie George and Bethan Ellis managed some partial repair work with a stand of 36 in 11 overs before George (23, 43) was bowled through the gate by Norris. Emily Arlott soon fell, brilliantly caught by wicketkeeper Eleanor Threlkeld diving at full stretch to her right off Naomi Dattani.Norris collected her fourth wicket when Ellis (33, 53) played across the line and was bowled middle stump. Threlkeld pounced again when Georgia Davis edged Hannah Jones and an untidy innings concluded in ramshackle fashion when Grace Potts and Hannah Baker differed on whether a single existed and the latter was run out by Alice Clarke’s throw.Clarke was then on the receiving end of a deadly throw, from Ellis, as she fell in the second over of Thunder’s reply. A fine ball from Potts left Seren Smale’s off stump leaning back and the score 25 for two but with such a low score to defend, Sparks needed to keep taking wickets. They didn’t, as Lamb and Mack settled quickly to ease their side towards victory.Lamb swung Ellis over mid-wicket for six to reach her half-century in 66 balls, Aussie import Mack followed to hers in 67 and victory was achieved in the most comfortable and leisurely fashion.