Metro Bank One-Day Cup quarter-final, Seat Unique Stadium, Bristol
Lancashire 177 (44.3 overs): Aspinwall 47, Wells 33; O Price 2-12, Payne 2-21
Gloucestershire 181-2 (24.5 overs): Hammond 109*, O Price 39
Gloucestershire won by eight wickets
Opener Miles Hammond hit an unbeaten 109 as Gloucestershire eased into the One-Day Cup semi-finals with an eight-wicket win over Lancashire at Bristol.
They will face Leicestershire at Grace Road on Tuesday after reaching a target of 178 with 25.1 overs to spare.
Lancashire, last year's runners-up, were bowled out for 177 despite 47 by 19-year-old Tom Aspinwall.
Hammond put on 125 with Ollie Price (39) and finished the job with three fours in an over off Aspinwall.
Gloucestershire had secured home advantage by beating Durham on Tuesday to take second place in their group and they made four changes, with David Payne - back from The Hundred - back in the side along with Graeme van Buuren, Tom Price and Ireland's Harry Tector.
Opener Chris Dent was not available for personal reasons, while Ben Wells, who hit 108 off 76 balls against Durham, had a sore hamstring.
Lancashire chose to bat after winning the toss but there was a steady fall of wickets after skipper Keaton Jennings edged a good ball from Payne to Gloucestershire captain and wicketkeeper James Bracey in only the second over.
Luke Wells, back in the team in place of Steven Croft, did his best to hold things together with a patient 33, but following a rain interruption he was stumped off an Ollie Price delivery that spun past the outside edge. That left the Red Rose on 84-6 and Matty Hurst soon followed, lbw to Paul van Meekeren.
Aspinwall and Tom Bailey gave their side some hope by adding 75 in 18 overs, but after the former was run out three runs short of 50, the innings came to an end in the 45th over as Jack Morley gave Payne (2-21) an easy return catch.
The visitors needed early wickets but could only produce one as Bailey jagged one back to clip the top of Bracey's leg stump and send him on his way for 12.
Hammond, playing only his third game in this year's competition, took the attack to the bowlers by hitting six sixes to reach a maiden List A hundred from only 82 deliveries faced as Gloucestershire, the 2015 winners, cruised towards an emphatic victory.
By then, Ollie Price had departed, caught off George Bell, but not before pushing his runs tally in the competition past 550 - the third highest - but Tector came out to keep Hammond company as the left-hander wrapped things up with over half of their overs still remaining.
Ageas Bowl: Hampshire v Worcestershire (11:00 BST)
Edgbaston: Warwickshire v Hampshire or Worcestershire (11:00)
Leicester: Leicestershire v Gloucestershire (14:00)