Against an unbeaten Nottinghamshire side at Edgbaston, Warwicks lost the toss and Notts elected to bat on a very sunny afternoon turned to evening
It was a decision which looked questionable as Hales was out at the end of the first over, caught by Darren Maddy to give Neil Carter a wicket.
Two balls later, Warwicks got their second wicket when Brown was caught by Clarke off the bowling of Chris Woakes.
Patel was out for 22 when a ball bowled by Barker gave Carter a catch and Wood was bowled by Imran Tahir to leave Warwicks on 40-4.
Notts were 62-4 at the end of the tenth over, but Chris Reid and David Hussey stepped up the run-rate.
With five overs to go, Notts had moved onto 113-4 with 22 runs coming in two overs. Hussey, the highest run scorer in Twenty/20 cricket, passed the fifty mark from 29 balls with a four but the 78 run partnership was ended when Jon Trott caught Chris Read who had made 26.
Fifteen runs came off the sixteenth over as Hussey found the middle of the bat to send the ball to the boundary.
Rikki Clarke bowled Mullaney with a yorker for the sixth wicket. Neil Carter was hit for 11 as Notts were 150-6 with two overs to go.
Hussey finished 81 not and Paul Franks 23 not out as Notts closed on 176-6.
Warwicks were without Ian Bell, who was on international duty and dropped Ian Westwood, were 30-0 at the end of third over.
Jon Trott and Neil Carter brought the fifty up from 29 deliveries before Carter was eventually out, caught by Paul Franks, for 35 from 19 balls to see Warwicks on 74-1.
Trott was out for 46, caught behind by Read, so Darren Maddy and Jim Troughton were left needing 71 to win from the final nine overs.
Unfortunately, Troughton, who was acting captain was bowled for three by Patel who bowled Darren Maddy (28) with his next ball.
Rikki Clarke came in on 116-4 which became five when Chopra was caught by Brown for three as the game was swinging back into the court of Nottinghamshire.
Clarke seized the mantle for Warwicks, hitting two sixes to take the required runs down to twenty runs from the last three overs whilst Ant Botha chipped in with a useful innings.
In the penultimate over, Clarke (33 not out), hit his third six of match from a low full toss and Ant Botha (21 not out) hit a four to give Warwicks a five wicket victory.
On Friday, Warwickshire travel to Worcestershire for a Twenty/20 game. Play at New Road is due to start at 5.30pm and commentary is avaiable from BBC Coventry & Warwickshire.