Barnet ended February without a League Two victory as the Bees fell to a 4-0 defeat against Bradford City at Underhill.
Things began to go wrong for the Bees just after the quarter hour as Darren Dennehy gave away a penalty and was dismissed for a foul on Craig Fagan.
The striker fired home the spot kick and Barnet fell further behind as Will Atkinson finished well.
Despite a dogged second half display the Bees conceded a third after a brilliant individual effort from Kyle Reid.
The defeat was rounded off late on when Nakhi Wells skipped past Liam O’Brien to roll the ball home.
Sanchez's line-up contained a surprise as O’Brien replaced Dean Brill in the Bees goal.
There were three further changes to his side as Jack Saville, Dennehy and Ricky Holmes all returned to the starting XI.
It was a very subdued start to the game and neither side threatened to break the deadlock in the opening minutes.
O’Brien’s first stop of the night was to tip away a fierce strike from Dean Smalley before watching an Andrew Davies header drift wide.
However, the Bees hopes of taking three points from the game were hit 16 minutes into the contest.
A quick interchange of passes got Fagan in behind the Barnet defence and Dennehy clipped the heels of the striker who went down.
Referee Roger East awarded the Bantams a spot kick and sent Dennehy off. Fagan decided to take the penalty and fired the ball into O’Brien’s bottom left corner.
A reshuffle in the Barnet defence saw Michael Hector move from right-back to centre-halve while Kamdjo replaced Hector’s vacated position.
The Bees performance improved after going down to ten men and they moved the ball well in midfield.
Saville and Kamdjo both had headers easily stopped by Jon McLaughlin in the Bradford goal before the visitors doubled their lead.
The lively Reid received the ball on the touchline, scampered past Kamdjo and delivered a low cross.
First-half Bantams substitute Atkinson reacted well and his half volley beat O’Brien at his near post and give the visitors a 2-0 lead at the break.
Sanchez made a change at the interval as Holmes was replaced by Charlie Taylor.
The Bees boss was forced into another change minutes after the restart as Saville hobbled off the pitch, on in his place was Jordan Mustoe.
Barnet continued to fight to regain a foothold in the game but it looked like a battle that they would not win.
All hope of a comeback was pretty much ended when the Bantams grabbed a third goal.
Reid, who had moments earlier cleared the south stand with a shot, tricked his way past Paul Downing and fired a low shot past O’Brien.
The second period was understandably controlled by the visitors and Fagan nearly scored Bradford's fourth only to be denied by O’Brien.
Barnet tested the Bantams goal a few of times after the break. First Izale McLeod sent a low shot goalwards that was easily dealt with by McLaughlin.
Sam Deering, who didn’t stop working throughout the game, also forced the Bradford stopper into action but it was an easy save for the keeper.
Taylor had a good chance from a Byrne free-kick but he could only head the drilled cross over the bar.
The loss was compounded in the closing moments as substitute Wells ran on to a long pass to skip past the goalkeeper and roll the ball home.
The game ended on a sour note for Barnet as following the goal Hector and McLeod had to be pulled apart by their team-mates.
The Bees will hope to put this performance behind them and are back at Underhill on Saturday as they host Rotherham United.
Barnet: O’Brien; Hector, Downing, Dennehy, Saville; Byrne, Kamdjo, Hughes, Deering; Holmes, McLeod.
Barnet substitutes: Brill, N’Diaye, Obita, Taylor, Mustoe.
Bradford City: McLaughlin, Kozluk, Oliver, Davies, Seip; Smalley, Ravenhill, Jones, Reid, Flynn, Fagan.
Bradford City: Fry, Annerson Wells, Bullock, Atkinson.