Tom Smith played a key role with bat and ball as Gloucestershire kept their hopes of defending the Royal London One-Day Cup alive with a 51-run South Group win over Sussex at Cheltenham.

In a match billed as must-win for both lowly placed teams, the hosts posted 242 for eight after losing the toss, Michael Klinger contributing 46 and Smith 43 not out. Chris Jordan claimed three for 55 and leg-spinner Will Beer two for 38.

In reply the Sharks could manage only 191 all out, despite an excellent unbeaten 87 from 21-year-old Harry Finch, left-arm spinner Smith taking 4 for 26 from his ten overs.

Sussex were not helped by the absence of their overseas pace bowler Mustafizur Rahman who is now in England but who picked up an injury after his first game for the county - one in which he was termed "a very special bowler" by his captain Luke Wright after demolishing Essex in the NatWest Blast.

The result took Gloucestershire to four points from five games, while Sussex remain on just two.

Gloucestershire lost wickets too regularly to gain much momentum to their innings. Chris Dent had already been dropped when falling early on for ten and it was 49 for 2 when Ian Cockbain was caught behind for eight in the ninth over.

Hamish Marshall's disappointing last Cheltenham Festival ended when he was bowled off inside edge by Jordan for 11 before Beer struck a major blow in the 22nd over.

Klinger had looked in prime form moving to 46 off 66 balls, with 6 fours, when adjudged lbw pushing forward. It may have been a case of the ball striking pad before bat, but the Gloucestershire captain was clearly unhappy with the decision.

Beer also removed Benny Howell for 19 and when Graeme van Buuren was bowled by Jordan for 38 off another inside edge Gloucestershire were becalmed on 155 for 6 in the 35th over.

Kieran Noema-Barnett (29) hit the only six of the innings over mid-wicket off Danny Briggs, but it was Smith who did most to bolster the modest total, facing 46 balls and hitting 3 fours.

Young wicketkeeper Patrick Grieshaber contributed a bright 20 at the death, but Gloucestershire looked to be short of a par score.

Soon, however, the home bowlers were striking back. Ed Joyce mistimed a back-foot shot to be caught at mid-wicket off Matt Taylor and when Craig Miles had Philip Salt caught behind it was 19 for 2.

Dangerman Luke Wright played a poor shot off Taylor on 18, chipping a catch to mid-on and Gloucestershire were right in the game at 43 for 3 in the ninth over.

Chris Nash was bowled off a bottom edge by Smith for six, but Finch and Ben Brown than gave Sussex hope with a stand of 70 in 19.4 overs before Brown, on 39, square drove Howell to Cockbain at backward point.

When Smith had Chris Jordan caught behind for 14, Sussex were left needing 84 off the last ten overs with only four wickets in hand.

Smith then took a fine caught and bowled at full tilt after Jofra Archer had skied the ball back over his head and had Ajmal Shahzad well held at deep mid-wicket by Dent.

Beer was run out and when last man Briggs was bowled by Howell, it left Finch, who faced 115 balls and hit 8 fours and a six, high and dry after a fine personal effort.