Warwickshire booked a Royal London Cup home semi-final against Somerset by defeating Essex Eagles by 70 runs at sun-drenched Edgbaston.

Jonathan Trott’s 20th limited-overs century – (101 from 124 balls with nine fours) – supported by Laurie Evans (70, 53 balls, three fours, three sixes) and Tim Ambrose (60, 74 balls, five fours) lifted the Bears to an imposing 283 for seven.

After a promising start Essex then slid to 213 all out, succumbing mainly to the spinners who shared the first six wickets, Jeetan Patel taking three for 32 and Josh Poysden three for 46.

Warwickshire chose to bat and began briskly with Trott and Sam Hain adding 41 in 46 balls before the latter, having pulled Graham Napier for six, was bowled next ball. Ian Bell then edged David Masters behind for a fourth-ball duck, triggering a sequence of 20 balls without a run off the bat.

From that slow start, Trott and Ambrose accelerated to add 136 in 27 overs and, after the latter chipped Napier to mid-wicket, Evans maintained the momentum. He helped add 49 in seven overs with Trott before the former England player, his century just greeted by a standing ovation, was stumped off Ashar Zaidi.

Essex, fielding very well, fought back as Chris Woakes fired Ryan ten Doeschate to point and the 45th over, from Napier, yielded just a single and the wicket of Rikki Clarke, caught at square-leg. But Evans and Ateeq Javid added 21 in 22 balls to get the score moving again and then, after Javid was caught at long on, Evans improvised brilliantly in the penultimate over, 14 runs off three balls from Napier including ten from two reverse-lapped to third man.

The Eagles’ reply was robustly launched by Nick Browne (39, 37 balls, six fours) and Tom Westley (61, 73 balls, five fours) with a run-a-ball stand of 75. But when Warwickshire turned to tandem spin the switch work spectacularly, six wickets falling in 15 overs.

Browne was stumped off Javid’s fourth ball, Jesse Ryder’s charge was defeated by Poysden’s turn and Ravi Bopara chopped Jeetan Patel to point.

Jaik Mickleburgh chipped a return catch to Poysden, Zaidi lifted Javid to mid-off and when Poysden trapped Westley lbw, Essex had slumped from 75 without loss to 134 for six.

Ten Doeschate (53, 52 balls, five fours and a six) and Foster added 33 in seven overs to keep their side in the hunt but after Foster chipped Clarke to mid-wicket, Ten Doeschate could only deliver a blow or two in vain before falling lbw to Patel.