Wicketkeeper-batter Skye Thomas made an outstanding 55 not out off 38 balls on her senior Lancashire debut to secure a four-wicket victory for her side against Durham at Emirates Old Trafford.

Having posted just 132 for 6 in their 20 overs with skipper Hollie Armitage making 30 and Venus Weerappuli taking 2 for 20, Durham rose to the task of defending that low score in impressive fashion.

Heather Graham took two wickets as Lancashire slumped to 75 for 6 in the 13th over but Thomas and the experienced Kate Cross put on an unbroken 60 in seven overs to put a dent in the record of a side who will appear at Blast Finals Day on Friday.

Durham’s high-quality top order were never able to cut loose and were restricted to 60 for 2 at the midpoint of their side’s innings. By then they had lost Katherine Fraser, who was yorked by the T20 debutant Olivia Brinsden for 17 and Armitage, caught and bowled by Darcey Carter for 30.

The visitors’ score had only reached 90 after 15 overs and by that point they had lost Bess Heath for 18 and Graham for a single. Durham’s decline continued as they lost Mia Rogers, leg-before to Sophie Morris for 3 and Emily Windsor, who became Thomas’s first victim in professional cricket when she stumped the Durham batter off Weerappuli for 27.

Grace Thompson revived her side’s fortunes a little when she made 28 off 12 balls, an effort that included the two sixes of the innings, but even the 13 runs conceded by Cross in her final over still left the total the wrong side of par on a hard wicket.

Lancashire’s hopes of securing a morale-boosting win were rocked when they lost three wickets in the powerplay. Stand-in skipper Eve Jones and Carter were both caught in the ring for 2 and 3 respectively, but the vital wicket of Meg Lanning was taken by Fraser, who bowled the great Australian batter for 15.

Those reverses left the home side on 40 for 3 after the powerplay and things got no better for them when Olivia Cunliffe was caught in the deep off Katie Levick for 2 and Dani Collins, having made a 22-ball 20, pulled Sophia Turner straight to Trudy Johnson behind square on the leg side.

When Fi Morris was bowled by Turner for 8, Lancashire were 75 for 6 in the 13th over but Thomas and Cross’s combined to good effect to leave 24 needed off the last three overs. Thomas and Cross both hit Graham for sixes in the penultimate over to all but settle matter and Lancashire’s victory was clinched when Thomas drove Turner through the covers off the fourth ball of the final over.