Yorkshire 329 for 3 (Duke 125, G Hill 90*) beat Leicestershire 327 for 7 (Harris 127, L Hill 108, Waite 5-59) by seven wickets
A first century in senior cricket by 19-year-old Harry Duke led a youthful Yorkshire side to a seven-wicket Royal London Cup victory over Leicestershire, eclipsing hundreds by Australia star Marcus Harris and captain Lewis Hill for the home side in a high-scoring 50-over contest.
Harris, whose 127 was his maiden List A ton, and Hill (108) shared a third-wicket partnership of 212 as Leicestershire posted 327 for 7, despite Yorkshire seamer Matthew Waite's first five-wicket haul in List A cricket.
It looked a daunting target after Will Fraine (45) and Gary Ballance (43) had both fallen when well set, with the hopes of a depleted Yorkshire side seeming to rest on their shoulders, but wicketkeeper-batsman Duke and 20-year-old George Hill - like Duke playing in only his second List A match - won the day for their team with a partnership of 172 in 33 overs.
Duke was bowled by Ed Barnes for 125 before Hill (90 not out) and Jonny Tattersall saw their side over the line with 13 balls to spare.
At 19 years 322 days, Duke is the youngest Yorkshire player to make a List A century since Sachin Tendulkar (19 yrs, 100 days) in 1992.
After Leicestershire won the toss, they lost George Rhodes in the first over, picking up two boundaries before being bowled off an inside edge by Waite.
The Powerplay finished with the home side 49 for 1. Rishi Patel then chipped straight to extra cover as 19-year-old pace bowler Matthew Revis claimed his first List A wicket in his second appearance.
Harris, missed on 35 when Dom Bess, diving to his left, failed to take a return catch, reached his half-century from 69 balls, Lewis Hill joining him on that mark from 47 balls as the partnership moved into three figures, Harris passing his previous highest List A score of 84 before moving to his hundred off 114 balls.
As Waite returned, Harris cut to backward point to be third out at 261 and Leicestershire lost four wickets in the last six overs, although there was still time for Hill to complete his second List A hundred off 96 balls before holing out to deep square leg off Waite, who also dismissed Arron Lilley and Louis Kimber to catches in the deep.
Yorkshire passed Leicestershire's Powerplay score in the ninth over, but had a setback when Fraine was caught behind, pushing tentatively at a ball from Wright. Ballance maintained the momentum but, after the industrious Duke had raised his fifty from 59 balls, was caught at backward point, reaching for a wide ball from Dieter Klein.
Hill had a life on 12, Wright failing to hold on to a difficult chance to mid-off that would have given 16-year-old debutant Rehan Ahmed a maiden wicket with his leg spin. It would prove an expensive miss.
The two young batters thereafter played superbly, running well between the wickets, rarely missing an opportunity to keep the scoreboard moving. The 39th over saw their partnership into three figures, Hill go to fifty with a six over Ahmed's head and Duke complete his maiden century off 111 balls.