Notts Outlaws missed the chance to seal their place in the semi-finals of the Yorkshire Bank 40 as Sussex Sharks reached a daunting target of 291 to win by four wickets at the BrightonandHoveJobs.com County Ground.
They were led to victory by skipper Ed Joyce, who carried his bat for an unbeaten 123, the 13th one-day century of his career.
Opener Alex Hales made 101 and David Hussey 82 as Nottinghamshire plundered 105 off the last 10 overs to post a formidable total of 290 for five.
But Luke Wright and Joyce launched the reply with 112 off 13 overs and, even when the former fell for 62, Matt Machan, whose 51 came off just 28 balls, maintained the momentum.
Sussex wobbled briefly towards the end of their chase before they got home with nine balls to spare.
Notts now need to beat Kent Spitfires at Canterbury in their final game on August 26 to make sure of their place in the last four.
The Outlaws made a bad start after choosing to bat.
Michael Lumb was lbw to the first legal delivery from Lewis Hatchett and the same bowler picked up a second wicket in the third over. James Taylor, who played for Sussex last month as a guest against Australia, was superbly caught low down by Chris Jordan at slip to leave the Outlaws 11 for two.
But that was Sussex's last success for 16 overs as Hales and Samit Patel rebuilt the innings with a stand of 102 before Chris Liddle had Patel caught on the long-leg boundary off a slog-sweep for 43.
Hales reached his fifty off 43 balls with a sixth boundary and went to his fourth List A hundred off a further 44 deliveries with 11 fours and a pulled six off Jordan. Two balls after reaching three figures, he was superbly caught by Rory Hamilton-Brown running in from the long-on boundary.
Hussey had been dropped on 17 at short cover by Michael Yardy and made the most of the reprieve, adding 81 in 45 balls with Riki Wessels.
A score of 290 should have been defended but the Outlaws bowled poorly from the start and Sussex had 71 on the board at the end of the eight-over powerplay.
Wright, who made 114 on Tuesday against the Netherlands, was soon into his stride as he reached 50 from 33 balls and it was a surprise when he fell to a catch on the midwicket boundary after collecting three sixes and four fours.
He had given Sussex the perfect platform and Machan was soon taking the Outlaws' attack apart, reaching his half-century from just 25 balls.
He was caught at short fine-leg off Hussey but Sussex needed 83 from 17 overs at that stage and Joyce was in no mood to let the advantage slip despite a couple of late wickets.