Worcestershire 211 for 3 (Moeen 90) beat Northamptonshire 197 for 7 (Cobb 80, Ajmal 3-53) by 14 runs
England's Moeen Ali hit a dominant 90 off 50 balls - after being dropped before scoring - and took two catches to give Worcestershire their second NatWest T20 Blast victory by 14 runs over winless Northamptonshire at Wantage Road.
But the game will be remembered for one of the strangest field placings seen in English cricket for years.
The ploy developed as an extension of MS Dhoni's decision to stand back to the spinners while keeping for India in the Test series in England last summer.
The umpires, after consultation, allowed it. "In a game when you're trying to stop the opposition scoring, it's a legitimate tactic," Steve Rhodes, the Worcestershire director of cricket, said.
Moeen's second over - the 16th of the innings - saw Cox remove gloves and pads and go to fly-slip, with no one standing up to the stumps. Umpires Nick Cook and Graham Lloyd conferred at length and allowed play to continue, with Mitchell persisting in the tactic for the spinners from thereon.
"One of the things I challenged the coaches in the winter to do, was to try and come up with some ideas that might just knock the opposition off their guard a little bit," Rhodes said. "It came about when I watched MS Dhoni stand back to the spinners for India and I thought that was a great idea. Afterwards, he said he wanted another catcher around the corner and he felt he could do that himself, standing back. That's how it started us thinking about it."
Cobb said: "I saw Daryl Mitchell tell Ben Cox to go back and I thought he was going to keep from the edge of the ring. Then I turned around and saw him without pads or gloves on. It's in the Laws and they've obviously looked into it and there's no Law against it. You've just got to question whether it's in the spirit of the game. But that's probably because it's never been done before. When they first come out, these things usually get questioned and left alone."
Earlier, Moeen - who scored just 104 runs in the recent Test series against New Zealand - should have been caught from the first legitimate delivery of the game, after Worcestershire won the toss and batted first. Another England hopeful David Willey produced the edge, but Rory Kleinveldt put down the straightforward chance at slip.
Mitchell was also dropped in the next Willey over by Kleinveldt, albeit to a more difficult opportunity. And the opening pair exploited Northants' generosity to put on 52 in the first six overs.
Northants - the only county without a T20 win so far - appeared to lose confidence when Moeen stepped up the assault against Shahid Afridi. Using his international class, he lofted over extra-cover and cut through backward point, before viciously pulling over midwicket for six that brought up a speedy 50 off 32 balls.
Mitchell was bowled by Afridi for 43 in the thirteenth, with 131 on the board, and Moeen's momentum was only checked by a brilliant one-handed catch by Northamptonshire captain Alex Wakely at cover as he drove at Steven Crook. His 90 included 5 sixes and 11 fours. The home attack looked lacklustre and conceded eight wides in all. Worcestershire's total of 211 for 3 was the highest on the ground, beating Northants' 207 for 4 against Glamorgan in 2008.
In the chase of 212, Richard Levi and Josh Cobb's second wicket partnership resulted in 65 runs in six overs but Northamptonshire's reply never received the same level of impetus. Cobb's first white-ball fifty in Steelback colours came off 31 balls.
Saeed Ajmal's opening spell - his first in England since remodelling his action in an ICC clinic - produced three overs going for 44 runs.
Northants needed 57 off 23 balls when Shahid Afridi came to the crease and despite two big sixes off Joe Leach, Ajmal returned to have his Pakistani colleague caught by Moeen at long-on with Cobb falling two balls later in the same manner. Ajmal finished with figures of 3 for 53.
Cobb's 80 off 44 balls which included six sixes, was his highest score in T20 cricket and it helped Northants post 197 for 7, which in itself was the third highest T20 score on the ground, but it was the visitors who claimed victory by 14 runs and more to spare than the margin suggested.