Sadler says players 'devastated' as dramatic Bears defeat edges Northants closer to the drop
It is a result that effectively relegates rock-bottom County from the LV= Insurance Championship Division One, as they are 32 points adrift of safety with just two matches remaining, which are against leaders Surrey and second-placed Essex.
A win against Bears would have kept Northants right in the hunt to stay up, and after day three was washed out, negotiations between the captains and coaches ahead of play led to the County agreeing to set the home side what looked a very generous 176 to win in 60 overs after a couple of early declarations.
The Bears recovered through the efforts of Ed Barnard (41) and Michael Burgess, but Northants kept plugging away and when Jack White claimed the wicket of Craig Miles they were up against it at 124 for eight - still needing 52 to win.
But Burgess, who made 78 not out, and Oliver Hannon-Dolby (9no) steered their side to a narrow victory, with the County left to rue a couple of dropped catches along the way.
Sanderson ended with superb figures of five for 42 from 17 overs while White claimed two for 59, but it wasn't enough.
"I'm really proud of our lads as they fought and fought and fought," said Sadler.
"We were behind the eight-ball and the odds were against us but all of a sudden we made them panic and put them under some serious pressure.
"Yes, it is frustrating and really disappointing, a great game for the neutral, but ultimately we felt like we could have won the game which is why the players are devastated."
And on the morning shenanigans that saw the teams set up the run-chase, the Northants head coach admitted it wasn't an ideal situation, said the outcome more than justified what happened.
"It was a tough one in the morning, negotiating," he admitted. "They wanted a lot less and we wanted a lot more in that run chase.
"But we didn't have any cards to play, our over-rate was down and time was of the essence so we had to take it.
"The first session of the day was not what anybody wants to see at this level, we know that, but the game made up for it in the second and third sessions."
Warwickshire coach Mark Robinson said: "We didn't want to chase more than that because we knew from the three days we have played the ball has gone past the bat a lot.
"They have got an excellent opening bowling partnership so we knew it wouldn't be easy. From 20 for five you don't win many games so it was an excellent comeback.
"Burgy and Barny batted really well and then suddenly we were eight down, but Burgy is still there batting beautifully and Olly comes in with his great character and great heart.
"I feel for Northamptonshire who are like us this time last year, giving it everything to try to stay up.
"They showed a lot of heart and bowled really well, especially Sanderson and White."
Northants are back in action next Tuesday when they take on Surrey at the Oval.
The Londoners are 18 points clear at the top, and can win the title if they beat Northants and Essex fail to see off Hampshire in their match at Chelmsford.