Marcus Trecothick continued his impressive early-season form with his second hundred against Glamorgan in the space of five days.

The England opener followed up his 147 in the CricInfo Championship match with a 118-ball hundred today that was the backbone of his side's six-wicket victory in the opening Benson & Hedges Cup zonal match.

Trescothick's performance was all the more impressive as he was Somerset's captain for the day in the absence of the injured Jamie Cox.

And the left-hander's form will have given the England management great encouragement with the Test series against Pakistan starting in just over a fortnight.

Replying to Glamorgan's 233-6, Somerset reached the winning line with three overs to spare.

Trescothick, who won the Gold Award, was given fine support by Keith Dutch who supplied a Benson-best of 55 in a second-wicket stand of 121 in 25 overs.

Glamorgan, last season's B&H finalists, won the toss but a solid start was marred by three unnecessary run-outs of top-order batsmen.

Steve James was run out by 10 yards in a mix-up with Mike Powell, who was also involved in the dismissals of Adrian Dale and Matthew Maynard.

Powell and Maynard looked to have rescued the Glamorgan innings with 84 in 15 overs before the former county captain was out of his ground attempting a third run.

Darren Thomas and Adrian Shaw added 43 in six overs to post a competitive total on a slowish Cardiff pitch.

But Glamorgan's bowling was too wayward at the start of the Somerset innings and Trescothick punished anything with width until he was out four overs from the end.

© CricInfo Ltd.