In glorious weather at Edgbaston, Northants, who included England international Monty Panesar, whose mother has links with the city of Coventry, won the toss and opted to bat first.
They lost Ian Harvey with the score on eighteen when he was caught by Stefan Piolet from the bowling of Neil Carter.
Chris Woakes back in for Jimmy Anyon and Keith Barker also bowled in the first five overs and took some punishment from White and Wessels with 34 runs coming off Barker's one over and Woakes' two.
Ricky Wessels who had hit two fours and a six in consecutive balls was eventually out for 28 when he was caught by Ant Botha off the bowling of Stefan Piolet.
Northants, who have won all three of their Twenty/20 matches, were 78-2 after ten overs. Rob White hit successive boundaries to reach his half century as the visitors looked set to run up a big score.
Piolet eventually bowled White for 59 to leave the score on 112-3 in the 14th over and then Andy Hall went for 19 when he was stumped by Ambrose to give Jeetan Patel his first wicket.
With Van Der Vath and Crook at the same end, Keith Barker ran Crook out for the fifth wicket.
Van Der Vath was caught by Piolet on the boundary before former Rochdale footballer Keith Barker dropped a catch. He was shown how to do it when Jim Troughton took a brilliant catch to remove Wiley in the 19th over.
Northants scored only five runs in the final over and closed on 155-7.
Jon Trott and Neil Carter opened the batting for Warwicks. They took six off the first over and were relieved in the first ball of the second over when Panesar dropped Carter who had made 22 in his first eight balls, hitting three fours and a six.
He finally went after making 25 from 12 balls in thirteen minutes when he was caught skying one. Three fours from Jon Trott had Warwicks at 41-1 after four overs.
Former Warwickshire man Lee Daggett had a bowl and took the wicket of Jim Troughton for five, caught by Ian Harvey.
Coventrian Ian Bell came in, in the sixth over and was off the mark first ball with a single. With the restrictions over and Warwicks 63-2, Monty Panesar came on and was hit first ball by Bell for four.
Bell was dropped with the score on 93-2 but the next chance had Jon Trott caught by Crook for 44.
It proved to be the turning point as Tim Ambrose came in to partner Bell. The one hundred came up in the 13th over as Panesar completed his four overs for 22 runs without a wicket.
Unfortunately, Ambrose only made three before being caught for the fourth wicket and then Bell fell victim to Harvey for 23 to leave Warwicks 108-5 in the 15th over.
Needing nine an over, dot balls were becoming too plentiful for Warwicks. Westwood (5) was run out looking for a second run as the game swung firmly back into the favour of Northamptonshire.
Chris Woakes was swinging and missing and when he did connect, he was was only scoring singles.
Warwicks needed 29 off the last over and most of the crowd started to leave
as they ended on 131-6 to lose the match by 24 runs.
Warwickshire play Gloucestershire on Thursday. Play is due to start at 5.30pm. Commentary is available from 6pm on BBC Coventry & Warwickshire. This wlll be their last Twenty/20 match for over a fortnight due to the Twenty/20 World Cup.
Warwicks will be in action however, with a County Championship game at Edgbaston against Nottinghamshire on Saturday.