Michael Lumb’s third successive 50-over century proved in vain as Jennings smashed 10 from the final two balls to clinch a dramatic victory.
Durham won by two wickets under the Duckworth-Lewis method, reaching a revised target of 252 from 37 overs when, with nine needed, Jennings closed the match with a six and four – after eight overs without a single boundary
Jennings’ late burst spoilt the excellent effort of Harry Gurney, who had figures of 5-42 until a full-toss was launched over midwicket by the left-handed Durham batsman, who then drove the final ball between mid-off and extra cover to seal the triumph.
Michael Richardson almost took Durham to the line with a List-A best of 64 off 58 balls, while veteran Paul Collingwood’s 69 off 65 was also crucial.
In a match interrupted five times by drizzle, Nottinghamshire may have had cause to regret choosing to bat as they totalled 274-5 in 42 overs.
Lumb made 105 to take his aggregate to 422 at an average of 140.66, but, with hindsight, the visitors would have felt they did not go quickly enough in reaching 124-1e after 25 overs.
The innings reached a crescendo with 48 off the last four as Samit Patel made 40 off 25 deliveries and Dan Christian thrashed 57 off 43 before he was run out off the last ball of the innings.
Durham raced to 32-0 after four overs before being halted by their innings’ only break. Gurney knocked out Mark Stoneman’s middle stump with the third ball on the resumption and quickly struck twice more.
Collingwood joined Phil Mustard on 54 for three and dominated a stand of 75 before the keeper was lbw for 47, trying to sweep Patel.
Collingwood swept to a 40-ball half-century by cutting Jake Ball for his sixth four and when Richardson pulled a Patel long-hop for six Durham needed 105 off 15.
They had the target down to 62 off eight when Collingwood was superbly caught by Brendan Taylor at long-off off Patel. Richardson kept going until three balls from the end, when he holed at deep midwicket off Gurney. It looked all over, but Jennings had other ideas.
The One-Day Cup now takes a break until July 24.
Durham head to Northants tomorrow night as the NatWest T20 Blast resumes.