The Clarets looked to be heading for a draw until Brownhill delivered the sting in the fourth minute of added-on time.
Burnley had to come from behind after Callum Lang had given Pompey a lead against the run of play in the first half.
Jeremy Sarmiento levelled just two minutes after coming on as a second-half substitute, the Brighton loan signing firing inside the far post with a curling effort from the left side of the area.
Portsmouth had done their best to eat up the clock with a series of time-consuming injuries and substitutions a, before Brownhill struck.
Clarets boss Scott Parker insisted the ball fell to the right man in the dying minutes given the midfielder’s experience and composure in crunch moments.
“He gives you every bit of that experience and composure,” said Parker.
“He understands and has the nous around the football pitch and this division.
Denne historien er fra September 22, 2024-utgaven av The Football League Paper.
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Denne historien er fra September 22, 2024-utgaven av The Football League Paper.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
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FUMING GRANT'S BLAST PAYS OFF
CHOICE words from Grant McCann at half-time did the trick as Doncaster Rovers came back to secure a point against classy Notts County.
BOSS MARTI'S ON A MISSION TO RESCUE R'S ALL OVER AGAIN
ARTI Cifuentes proved he was up for a challenge when he took the manager’s job at QPR just over a year ago.
HUSTLE FROM RUSSELL NETS DERBY SPOILS
HEAD coach Darrell Clarke praised goalscorer Jon Russell as his Barnsley side earned all three points in a home victory over South Yorkshire rivals Rotherham United.
DAVIES AGONY AS BLUES BLOW IT
ADEJECTED Chris Davies gave a bleak assessment of his Birmingham City side’s draw against Northampton Town.
WARNOCK: ONLY A GAME? IT'S LIFE OR DEATH IN SHEFFIELD!
JUST another game? Don’t pull that one on Neil Warnock, a Sheffield native, boyhood Blade and managerial veteran of nine Steel City derbies.
BISHOP AT THE HEART OF POMPEY WIN
COLBY Bishop’s spectacular return after heart surgery was a well-kept secret, said Portsmouth manager John Mousinho.
ACE VAKOUN CLEANS UP FOR THE HORNETS
VAKOUN Bayo took the plaudits once more after his goal sunk Oxford on Friday.
ANDI'S AT DOUBLE TO SPARK AWAY JOY
BLACKBURN Rovers boss John Eustace believes his team gave a text-book performance to get a first away win of the league season at Cardiff.
COV CATCH BLACK CATS NAPPING
SUNDERLAND head coach Regis le Bris was frustrated his players couldn’t build on two moments of first half magic that should have seen off managerless Coventry City at the Stadium of Light.
FARKE: WE HAVE THE WINNING MENTALITY TO STAY COURSE
Pressure mounts on Hoops manager
