Ball continues his fruitful competition with 4 for 34 before Vaughan, against the county his father captained, struck 95 in an efficient chase completed with five balls to spare
York: Yorkshire 247, Somerset 252-4 - Somerset won by six wickets
Four-wicket seamer Jake Ball and opener Archie Vaughan, with a career best 95, starred as Somerset ended Yorkshire's 100 per cent winning start to this season's One Day Cup by bowling the Group B leaders out for 247 at York and then chasing confidently.
Somerset joined their hosts on 12 points at the top of the table at the halfway stage in the group campaign courtesy of this six-wicket win with five balls remaining. Both counties having won three and lost one.
Yorkshire still hold sway courtesy of a superior net run-rate. But they were second best on a used Clifton Park pitch.
Yorkshire lost wickets in clusters at either end of a scrambling innings which saw ex-England limited overs quick Ball take an excellent four for 34 from 9.4 overs and Matthew Revis top-score with a middle-order List A best of 85 off as many balls.
Ball's best List A figures in just over six years preceded Sheffield-born teenager Vaughan's classy 127-ball effort with 11 fours. It was ironic that this senior best should come against the county for whom his father Michael starred.
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Ball took his wicket tally in the One Day Cup to seven (Getty Images)
Without the injured in-form opener Imam-Ul-Haq, Yorkshire lost Adam Lyth, bowled by a beauty from Ball, Will Luxton run out next ball - 22 for two in the seventh - and James Wharton caught behind one-handed going low to his right by James Rew off Ben Green.
Luxton misjudged a push to mid-off, where Josh Thomas misfielded before recovering to throw the non-striker's stumps down.
Revis, who hit nine fours, oozed confidence following three recent Championship centuries and a 69 earlier in this competition as Yorkshire compiled nothing more than a workable total.
George Hill (41) and Dan Moriarty (30) - who hit the hosts' only sixes - helped them along before Ball returned to wrap up the innings with eight balls unbowled.
Opener Vaughan, in his first competitive senior career appearance against his birth county, steered Somerset's stress-free chase.
He was particularly strong off the back foot on either side of the wicket, reaching his fifty off 65 balls.
Goldsworthy fell at 111 for 2 but the 19-year-old continued on unflustered, sharing 64 with his captain James Rew. Though he was bowled looking to go over the top against Dom Bess's off-spin, Rew finished unbeaten 53 off 62, while brother Thomas also contributed 31.
Lead image: John Clifton/SWPix.com