Kiran Carlson won the toss for the first time in seven games and decided to bowl with an unfamiliar attack short on pace, while the Foxes changed three of their seamers.

An action-packed first hour saw Sol Budinger blast 33 off 19 balls, mainly off the medium pace of Andy Gorvin, before carving him to third man, where Norton took a fine diving catch.

Rishi Patel fell to the economical Zain Ul Hassan for si,x and Abergavenny product Norton then claimed the prime wicket of Pakistan captain Shan Masood as his first county scalp, lbw for 18.

But Leicestershire's experienced pair of Hill and Handscomb went on the counter-attackAddingng 84 in 13.1 overs before Handscomb was run out by a Henry Hurle direct hit.

Hill was still going strongly and forcing plenty of bowling changes, but Norton had him caught behind after hitting nine fours and a six in a dominant knock.

When Sam Wood (16) was run out by Tribe, the Foxes had to regroup before the final assault.

But Liam Trevaskis fell to Norton and Franco took the last three - fellow North Walian Roman Walker for 17, Chris Wright for 14 and Alex Green for 21 in the last over.

Glamorgan's reply saw Eddie Byrom (23) and Carlson (29, including three sixes) start strongly but fail to kick on as another 18-year-old, Alex Green, took two of the first three wickets.

Green had Will Smale caught off a no-ball, and that proved expensive for the Foxes as Smale started in an unusually restrained fashion, playing a support role to Tribe.

The Jersey opener, who had batted through 50 overs for his 122 not out at Worcester, reached three figures off 109 balls in another mature display.

Smale finally unveiled his ramp shot and opened up to pass 50 off 64 balls as the home side accelerated, with a dropped chance off Matt Salisbury on 68 probably coming too late to matter.

There was no pressure on the run-rate in the closing stages, and Tribe appropriately hit the winning four with 26 balls to spare.

Despite their One Day Cup struggles, both teams have high hopes of promotion in the Championship as Leicestershire and Glamorgan occupy the top two places with three rounds to play in September.

Glamorgan's Tom Norton told BBC Sport Wales:

"It was brilliant, stuff I'd dreamed about for a very long time, so it was a very good day, as I only knew I was playing 15 minutes before the toss.

"I was nervous going into the bowl, but once the first one landed, I was alright. You just have to enjoy it, and it was pretty special when the umpire's finger went up, a surreal feeling to get him (Shan Masood) out.

"It was one of my aims to get involved in (the first team) this year. I was a bit disappointed not to get a contract at the start of the tournament, so it was good to get one at the end.

"Hopefully, I'll get a contract and see where life takes me. I'm going out to Australia to play over there in October and experience life there.

"Mum's been a massive help for me at pretty much every game I've played and Dad driving me round, but all the coaches have helped me over the lastyearsyear including Darren Thomas with the under 18s."

Leicestershire coach Alfonso Thomas said:

"We were probably about 20 runs below par, and we didn't have anyone kicking on, as young Asa Tribe showed there were enough runs out there.

"A couple of guys got srts, but Glamorgan fielded superbly well and kept fighting with the ball; we were just not good enough today.

"I said to the lads to make sure we stay professional, we are still representing Leicestershire County Cricket Club, and the lads did that today, it's about pride.

"It will be nice if both these teams can go up to Division One or whatever it may be. The key for us is going into the last three games in September, trying to win all of them and hopefully lift the title."