Somerset 299 for 4 (Hildreth 110, Davies 94, Goldsworthy 57*) beat Derbyshire 298 (Hudson-Prentice 93, Guest 74, Baker 3-46, Green 3-64)
Hildreth required treatment for cramp and batted with a runner in the later stages of his innings, but guided a young side to victory with two overs to spare. Davies had led the way with with an imperious 72-ball innings, before Hildreth weighed in with 110, including nine fours and three sixes.
The visitors ran up 298 all out after losing the toss, Fynn Hudson-Prentice, who made 93, and Brooke Guest (74) hitting career-best List A scores, while 18-year-old seamer Sonny Baker claimed 3 for 46 on debut.
A crowd of well over 3,000 at the Cooper Associates County Ground saw Derbyshire reduced to 36 for 3 at the start. Baker, a product of Devon age-group cricket, had Harry Came and Tom Wood caught behind in a five-over spell of 2 for 14, while Jack Brooks accounted for Billy Godleman, caught at fine leg.
Guest and Hudson-Prentice exercised understandable caution and at the halfway stage of the innings had taken the score to 117 for 3. Hudson-Prentice took advantage of anything short to reach an impressive half-century off 60 balls, while Guest cleverly picked gaps in the field to move to fifty from 67 deliveries.
England spinner Jack Leach went for 18 off the 33rd over, Hudson-Prentice clearing the ropes for the second time. The stand of 142 with Guest was a Derbyshire List A record for the fourth wicket against Somerset. It ended when Hudson-Prentice was caught and bowled by new Somerset List A captain Ben Green, having hit 10 fours and two sixes.
After Anuj Dal had been run out by Brooks, Guest was caught at cover off seamer Kasey Aldridge, making his List A debut, to make it 224 for 6. Alex Thomson contributed 24 and last man Ravi Rampaul boosted Derbyshire's score with 3 sixes off Green before the last wicket fell in the final over.
Despite the early loss of Plymouth-born debutant Sam Young, caught behind down the leg side looking to glance off-spinner Thomson, Somerset were soon in charge on a true pitch. Davies took three fours off an over from Rampaul and looked in great touch. But George Bartlett flattered to deceive, carelessly pulling a short ball from Hudson-Prentice to Dal at deep square.
Hildreth began well and when Davies moved to an effortless fifty off 46 balls, with five fours and a six, home supporters were in high spirits. The pair continued to flourish, bringing up a hundred partnership from 98 balls before Hildreth went to a typically attractive half-century off 62 deliveries.
Davies fell to a catch in the deep, having struck 12 fours and a six. But Hildreth brought up the 200 with a pulled six off Ben Aitchison in the 35th over and found an equally positive partner in 20-year-old Lewis Goldsworthy, who celebrated his List A debut with a mature 57 not out, off 66 balls.
Hildreth struggled through the later stages of his innings, but it didn't stop him reaching three figures with a six over cover off Rampaul before falling with just 23 needed.