Glamorgan 301 for 8 (Byrom 108, Root 74) beat Somerset 298 for 7 (Umeed 116, Kellaway 3-49) by two wickets
In reply, the visitors made 301 for eight from 47.1 overs, Byrom striking 108 from 103 deliveries on the ground where he launched his county career. Kiran Carlson contributed 75 to a third-wicket stand of 142, while Billy Root hit 74 not out.
It was only Glamorgan’s third group win in seven games, while for Somerset a fifth defeat continued a disappointing campaign.
George Thomas ensured a brisk start to Somerset’s innings, lifting a six over fine leg off the second ball of the second over, sent down by Ruaidhri Smith, on his way to an attractive 41 off 28 balls.
Tim van der Gugten made a much-needed breakthrough for Glamorgan in the ninth over when Thomas was well caught low down by Smith at mid-on with the total on 60.
Umeed and Lewis Goldsworthy then put together a century stand in good time, Umeed moving to a stylish half-century off 66 balls, and Goldsworthy lending solid support as they took the score to 173 in the 32nd over.
When Goldsworthy holed out to deep square off Zain-ul-Hassan with his side looked set to make well in excess of 300. But Carlson began Glamorgan’s fightback by running out James Rew and Kellaway had begun a telling spell from the Marcus Trescothick Pavilion End.
The young spinner maintained an exemplary line and length to send back Sean Dickson, Umeed and Josh Thomas, preventing a late acceleration and keeping his side well in the game.
It was left to Danny Lamb (41) and George Bartlett (35 not out) to bolster Somerset’s score, but it looked no more than par on a true pitch with the sun out.
Glamorgan’s initial response was to lose two wickets in as many overs, Sam Northeast bowled between bat and pad by Jack Brooks and Colin Ingram brilliantly caught by wicketkeeper Rew, diving full length, off Ned Leonard to make it 13 for two.
But soon Byrom and Carlson were counter-attacking with a flurry of boundaries, Carlson greeting the introduction of J.T.Langridge with a six over backward point in the left-arm seamer’s first over.
Langridge’s first two overs went for 28 as the Glamorgan pair took the total to 88 for two after ten. Carlson raced to fifty off 29 balls, with 6 fours and 3 sixes, and Byrom soon followed, off 38 deliveries, with 10 fours.
The hundred stand occupied less than 12 overs as Somerset’s bowlers were put to the sword, not aided by some sloppy ground fielding. It was a surprise when with the score on 155, Carlson carelessly cut a catch to point off Lamb.
Byrom continued on his merry way and was on 80 when a shower interrupted play at 185 for three, with Glamorgan needing less than five an over.
The rain soon passed and an edge to third man for his 16th four took Byrom to his first List A hundred off 94 balls as Glamorgan closed in rapidly on their target, Root contributing a valuable 44-ball half-century.
Byrom was finally bowled by occasional leg-spinner Umeed, his first List A wicket. Kellaway, Alex Horton, ul Hassan and van der Gugten fell cheaply in the closing stages, Umeed finishing with three for 31, but Root stayed calm to see Glamorgan home.