Matt Windows hammered a brilliant 83-ball century as Gloucestershire condemned Northants to an 83 run NUL defeat at a sunny Cheltenham.
With Ian Harvey and Chris Taylor contributing half-centuries, the home side reached their highest ever total in the competition - a massive 344-6 from their 45 overs, having been put in.
Harvey set the tone by smashing 67 off just 34 balls with eight fours and three sixes in a murderous exhibition that drained the confidence of the Northants attack. He hit 18 off an over from Michael Strong and 21 off an over from Jason Brown.
Windows then kept the momentum going, blasting 10 fours and five sixes in his 117, made off 94 balls. It was his best ever limited overs score.
And Taylor celebrated the award of his county cap before the game by hitting 63 with eight fours and a six before retiring hurt with what appeared to be a neck injury and going to the local hospital for precautionary x-rays.
It was a sorry afternoon for the Northants' bowlers in bright sunshine as 212 of Gloucestershire's runs came in boundaries. Mike Strong conceding a record 99 runs from his nine overs (a new record for the most expensive analysis in the one-day league surpassing Dominic Cork's 96 conceded against Notts in a 50 over game in 1993, though he bowled only eight overs). Lesroy Weekes' four overs cost 49.
Northants needed to score the highest ever second innings score in any form of the competition if they are to win. Any hope the visitors had of getting neat the huge target disappeared when James Averis removed Mike Hussey, Graeme Swann and Mal Loye in his opening spell on the way to figures of 5-56.
Martyn Ball followed up by sending back Russell Warren and Adrian Rollins, who both threatened briefly before Tony Penberthy (52) and David Ripley (35) helped Northants to a respectable reply of 261 all out.
The results moved Gloucestershire away from the relegation zone but left their opposition deep in trouble, having won just two out of nine games.
Sussex go top of Division Two with victory over Middlesex.