Somerset 147 for 4 (Rossouw 67, Smeed 58) beat Essex 139 for 9 (Critchley 60, Pepper 37, de Lange 4-9, Davey 3-31) by six wickets

In a match reduced to 18 overs per side by rain, paceman de Lange - confined to the second XI for the County Championship season to date - included a double-wicket maiden in taking 4 for 9 from three overs as Essex posted 139 for 9 after losing the toss.

It meant a second win from two group matches for last season's runners-up, who look set for another successful T20 season.

Essex got off to a slow start after Somerset skipper Tom Abell had elected to field, losing openers Will Buttleman and Adam Rossington to Davey and Tom Lammonby respectively, off the first 14 balls.

But Critchley and Pepper got the innings on track, taking the score to 50 for 2 by the end of the six-over powerplay, Critchley striking three boundaries in the fourth over, sent down by Davey. Pepper reverse swept left-arm spinner Roelof van der Merwe for three fours in seventh over, as well as driving him through cover for a fourth boundary.

Critchley hit Lewis Gregory for six over point as the pair to the total to 83 by the end of the ninth over before de Lange took a decisive hand. Having conceded five from his first over, the strapping South African seamer had Pepper caught at mid-on, having faced 24 balls, and Paul Walter taken at fine leg for a duck in a tenth over that saw the Eagles fail to add to their score.

The spin duo of van der Merwe and Lewis Goldsworthy then bowled five overs in tandem for only 34 runs, Goldsworthy picking up the wicket of Tom Westley, as Somerset turned the screw. Critchley had reached a 32-ball fifty when rain interrupted play at the end of the 15th over, with Essex 117 for 5.

By the time the players returned to the field at 5.50pm, the match had been reduced to 18 overs. Their final three saw the Eagles lose two wickets to Davey and two to de Lange, including Critchley, who had struck six fours and two sixes.

Smeed ensured Somerset made a rapid start to their reply, lofting two sixes in the third over, bowled by Dan Sams, before Ben Allison had Tom Banton caught at deep midwicket for two.

The powerful Smeed collected his third and fourth maximums by smashing Sam Cook for six, four, six at the end of the fifth over, and by the end of the powerplay Somerset had raced to 69 for 1, Rossouw joining the party with a six over midwicket off Simon Harmer.

The South African left-hander built on his match-winning Somerset debut innings against Kent on Wednesday, hoisting left-arm spinner Aron Nijjar for 3 sixes in the ninth over, which saw Smeed reach a 25-ball half-century.

Rossouw cleared the ropes twice more off Critchley, while Smeed also treated the crowd to another six in the same over. Both fell late on, along with Tom Abell, but by then the outcome had long been settled.