Ferocious hitting by Tyron Henderson helped Middlesex to overcome Durham by eight wickets to reach their first Twenty20 Cup final at the Rose Bowl. They will play Kent Spitfires, the defending champions, who earlier in the day had beaten Essex Crusaders by 14 runs with a place in September’s inaugural Champions League in India as well as a place in the lucrative Stanford Super Series in Antigua.

Henderson, an all-rounder from Durban, struck 59 from 21 balls, including seven sixes in the day’s most impressive hitting display so far. He hit two successive sixes from Stephen Harmison and won the match with a similar hit from the Durham fast bowler, whose recall to the England squad for the Third Test against South Africa earlier in the day was soured.

Durham, one of the favourites for the competition, never looked likely of reaching the final after struggling to 138-6 off 20 overs. Tim Murtagh, the Middlesex seamer, put his team on track with three wickets, including both of Durham’s dangerous openers.

With Michael Di Venuto and Phil Mustard back in the pavilion, Paul Collingwood and Shivnarine Chanderpaul steadied Durham’s innings with 35 and 48 respectively, but were never able to accelerate much past a run a ball. Much of this was thanks to miserly bowling in tandem by the Middlesex spinners Shaun Udal and Murali Kartik, whose eight overs combined went for 36 runs.

Middlesex seemed to be cruising as it chased its target before stuttering. Billy Godleman and Ed Joyce, the openers, calmly took their team to a solid 65 without loss before Godleman went leg-before-wicket for 20 off the bowling of Gareth

Breese. Joyce followed soon after, stumped off Paul Wiseman for 41, but Middlesex recovered as the loss of the two wickets just brought Owais Shah and Henderson to the crease.

In the day’s first semi-final, Essex had also appeared to be cruising as it chased down Kent’s 173-7, but a pair of late run-outs swung the match and Essex could only make 159-8.

“They’re a nightmare, Twenty20s, when you’re in the middle of them,” Robert Key, the Kent captain, said. “They’re fantastic when you’re sitting back watching. But when you’ve won you think, ’What a great experience that was.’

“It’s daunting because one over changes the game.”

The game first looked to be tilting toward Kent when Graham Napier, who had been expected to be one of the stars of the day after scoring 152 not out from 52 balls last month, was dismissed for just three. He skied a delivery by Simon Cook and fell to a running catch from Kent captain Robert Key.

“He had so much build-up and there was so much focus on him and how good a destroyer of bowling he is,” Key said. “Unfortunately, nothing like that matters when you get in to these games.”

Grant Flower was then run out for 17 and Mark Pettini, the Essex captain, for 54 in the 15th over to leave Essex on 117-4, a position they never recovered from.