Just three days after producing one of their finest performances of the campaign with a vital home victory over Chesterfield, County somehow managed to conjure a mind-bendingly dire defensive display in a crazy encounter at Rodney Parade.
Christian Fuch's men shipped three second-half goals in a bizarre clash that saw seven players booked and County attacker Nathan Opoku red carded following his two bookable offences inside four minutes after the interval.
The Port, who fell to their equal worst hammering of a season increasingly shrouded by relegation fears, had trailed less than two minutes into the game as Alex Henderson profited to soft defending - Opoku had cancelled out that score after the half hour, though.
Despite illumination from midfielder Harrison Biggins and Joe Thomas at right-back, this odd clash really turned on two major incidents - the first on 51 minutes, Stanley's Isaac Sinclair, son of ex-England and West Ham star Trevor, not believing his luck as the seemingly mesmerized County rear-guard allowed his toe poke to trickle into the net.
Then, moments after being cautioned for a foul, borrowed Leicester City striker Opoku was rightfully red carded in the 70th minute for pole-axing Stanley's veteran raider Paddy Madden.
If the points hadn't been totally decided by then, they had been 12 minutes later. With Port's 10-men desperately seeking a lifeline, a sharp counter attack saw shaven-headed Madden blast a third for the visitors, Isaac Heath rubbing salt into home wounds with a fourth as we entered additional time.
The Exiles made the slightest of tweaks to the side that edged Chesterfield last Saturday - Thomas replacing Liam Shephard at right back, ex-Cardiff left-side defender Tom Davies restored, but to the bench.
John Doolan's Stanley, whose defensive strategy had spiked the guns of Walsall in a goalless draw up in the west Midlands last Saturday, drafted in former Plymouth linkman Conor Grant for defensive midfielder Seamus Conneely.
Accrington. who were making a arduous 426-mile round trip from east Lancashire spanning numerous motorways, sat in lower mid-table. But the visitors boasted impressive stats on the road, snatching eight from a potential 15 points and two successive away clean sheets. They were to improve that record here.
The Exiles were disastrously bitten by Stanley's attacking teeth just one minute and 55 seconds after kick off. Accrington skipper Shaun Whalley allowed to do the initial work on the edge of the box, before touching through for Henderson to easily beat Jordan Wright with a low finish.
The 21-year-old's goal had clearly stunned County. There was more danger from Henderson on 23 minutes, the youngster leaping between Port's Matt Baker and Ryan Delaney, his glance from Donald Love's deep cross flashing fractionally wide, as the Exiles creaked alarmingly.
With Biggins, ex-Wales international Matt Smith and the muscle of Ciaran Brennan sparking in central midfield, County, were starting to dominate possession against opponents operating a low press, always defending in numbers when any danger occurred.
All-action Biggins thundered a header into the midriff of Accrington stopper Ollie Wright, the borrowed Shrewsbury schemer then lifting a long-range screamer over the bar. But the Sheffield-born player was sculpting a Port leveller on 34 minutes.
Sheer persistency brushed off a challenge from Isaac Heath on the near touchline and with Stanley centre-back Devon Matthews dragged out of position, Opoku powered Biggins' volleyed cross into an empty net.
It was the Leicester City striker's fourth goal of the season, County threatening more damage as Biggins teed-up an advancing Anthony Glennon, the Scouse left-back's powerful drive just off target with Wright on red alert.
This feisty clash had a showed a fantastic tempo in an intriguing half. Tempers were fraying as Accrington struggled to stay in the contest, Matthews, Grant and Connor O'Brien cautioned in rapid succession for poor challenges - Port's Michael Spellman booked for diving by over-worked referee James Durkin.
But comic-cut defending had really cost County six minutes into the re-start, There appeared no menace as Madden offered a decoy in a central position. Accrington skipper Whalley threaded through for Sinclair, whose prod somehow rolled into the net with County's devastated defenders gazing on.
The Exiles rallied and were so nearly level on 55 minutes. Moments after Opoku powered over the bar, Spellman saw an effort booted clear by Farrend Rawson, Biggins then pulling his drive wide in the ensuing bedlam.
Yet the Port were seemingly indebted to keeper Wright as the clocked ticked down - the former Grimsby custodian springing low as his right hand beat away Love's angled rocket, but catastrophe for County was looming.
The strange contest was twisting away from Newport in the 70th minute - Opoku floored Madden and was sent packing by official Durkin, County substitute Ben Lloyd, one of five utilised, had seen yellow earlier.
There was more darkness for stricken County in the closing action as two Accrington counter attacks yielded maximum damage. Madden gleefully blasted a third for Stanley on 81 minutes, Heath's acute angled drive adding a fourth - via the near post - two minutes into additional time.
Newport County [4-3-3]
Jordan Wright
Joe Thomas
Matt Baker [C[
Ryan Delaney
Anthony Glennon
Ciaran Brennan
Matt Smith
Harrison Biggins
Michael Spellman
Nathan Opoku
Bobby Kamwa
Subs
Nik Tzanev ]GK]
Cameron Evans
Tom Davies for Glennon 80 mins
Lee Jenkins for Thomas 80 mins
James Crole for Spellman 65 mins
Ben Lloyd for Smith 45 mins
Tanatswa Nyakuhwa for Kamwa 80 mins
Accrington Stanley [3-4-2-1]
Ollie Wright
Donald Love
Farrend Rawson
Devon Matthews
Connor O'Brien
Conor Grant
Isaac Sinclair
Isaac Heath
Shaun Whalley [C]
Alex Henderson
Paddy Madden
Subs
Charlie Brown
Luke Butterfield for Henderson 71 mins
Charlie Caton
Shamus Conneely for Grant 56 mins
Michael Kelly [GK]
Freddie Sass for O'Brien 56 mins
Josh Woods for Madden 84 mins
Referee: James Durkin
Assistants: Harley Hetherington & David Middleton
Fourth Official: Richard J Morris
Attendance: 3,563 [55 ]