Warwickshire 157 for 7 (Maddy 49, Ambrose 40, Jordan 3-27) beat Sussex 149 for 7 (L Wright 44, C Wright 3-27) by eight runs
Chris Wright put in a fine display of one-day bowling as Warwickshire notched up their first win of their Yorkshire Bank 40 campaign and dent Sussex's hopes of a third successive appearance in the knockout stages.
Chasing a target of 158 in 21 overs after rain delayed the start of the until 7.30pm, Sussex were always up against it after losing Chris Nash and Rory Hamilton-Brown in the first five balls of their reply. Both were caught in the deep off top edges in Wright's first over and Wright returned to the attack in the 18th over to deliver another important blow when he had Mike Yardy taken on the midwicket boundary for 25.
On a pitch offering good pace and carry, Wright used the short ball expertly and only conceded 10 runs in his final two overs, which left Sussex needing 17 off the final over. The task proved beyond them when Boyd Rankin removed Matt Machan and Ben Brown with successive balls and they finished eight runs short.
Sussex's chase had been revived by a stand of 73 in 10 overs between Luke Wright and skipper Ed Joyce for the third wicket. Wright led the scoring with 44 off 35 balls and Joyce, who made an century for Ireland against Pakistan in Sunday's one-day international, gave him good support with 31 before the pair fell in successive overs from offspinner Jeetan Patel.
Warwickshire's total of 157 for 7 had been built around solid contributions from Tim Ambrose, with 40 and Darren Maddy's 48.
The Bears could only score 25 in the first four-over Powerplay and lost two wickets in the process. Will Porterfield was superbly caught one-handed by the diving Chris Jordan at slip and Jordan then had Bears' skipper Jim Troughton held at backward point off a top edge.
Ambrose and Virun Chopra steadied their side with a stand of 51 from 46 balls when Chopra was pinned leg before wicket by Yardy, working the ball to leg.
Ambrose hit a six and three fours before slicing Chris Liddle to backward point but by then Maddy was well into his stride. Three previous appearances in the YB40 had yielded just 11 runs but he put his poor form behind him. He struck three sixes, including two in the final over off Liddle, and four fours off just 25 balls before he was caught on the long-off boundary trying to reach 50 from the last ball of the innings.
Jordan was the best Sussex bowler with 3 for 27. An out-of-touch Rikki Clarke was bowled off an inside edge and Jordan also removed former Sussex player Stefan Piolet, who sliced a drive and was caught behind.