Pompey came out on top of their high-octane battle against Bristol Rovers to sit at the summit of League One with Peterborough.
Goals from Gareth Evans and Ronan Curtis handed the Blues a hard-earned 2-1 win at the Memorial Ground to equal the four straight wins to the 1980-81 season achieved by Frank Burrows' side.
Substitute Chris Lines fired home from the penalty spot on 75 minutes to cancel out Evans' 32nd-minute opener.
But within minutes he was seeing red after a high-footed challenge on Pompey sub Brett Pitman.
And the Gas were made to pay the price, with Curtis popping up with three minutes to go to hand Kenny Jackett's side an impressive victory.
In a fascinating first half, with both teams going for the jugular, Jamal Lowe handed Curtis the chance to silence the Memorial Ground as early as the fourth minute.
The Blues winger powered forward and looked up before firing an inch-perfect crossball into the path of the Irishman, yet Rovers keeper Adam Smith was equal to his effort.
Smith was called into action again in the 10th minute to punch away Oli Hawkins' header.
And as Pompey stood up to the test posed by their hosts, Evans fired wide on 15 minutes following two full-blooded tackles from Tom Taylor and then Jack Whatmough.
Kyle Bennett was enjoying his run-out against his former team-mates, and as his influence grew, so too did Rovers' threat in front of goal.
Ed Upson fired over from a free-kick on the edge of the Pompey penalty area, before Bennett teed up the unmarked Liam Sercombe, who could not test Blues keeper Craig MacGillivray.
Matt Clarke then produced a vital last-gasp tackle to deny Stefan Payne a clear sight of goal.
And as the noise levels grew among the home support, there was a sense - at least among the Memorial members - that a goal was in the offing.
Little did they know, however, that it would come at the other end.
A long punt forward from MacGillivray in the 32nd minute was flicked on firstly by Hawkins and then Curtis - and Evans was on hand to power home for his second goal of the season.
Bennett rallied the hosts by sending a 20-yard effort over the bar.
Meanwhile, MacGillivray had to be alert to deny Sercombe from 25 yards on the stroke of half-time.
Naylor had the first chance of the second half, firing over from the edge of the area.
A blow to the head for Clarke then stopped play for several minutes shortly afterwards.
And there was a good chance the Blues defender's head remained in a spin as Rovers went in search for an equaliser.
Nichols' curler from the edge of the box was parried by MacGillivray, and the keeper breathed a sigh of relief when Sercombe could only find the side-netting after he picked up the loose ball.
James Clarke then tried his luck with a rasping effort that was blocked, before Sercombe was appealing for a penalty after Ben Thompson got in the way of his effort.
Any hint of a handball was quickly dismissed, though, by referee Graham Salisbury.
An Evans effort that drifted wide of the post suggested Pompey had weathered the storm.
But they were soon back on level terms after another period of sustained Rovers pressure.
After MacGillivray had saved at his near post to deny Sercombe, a handball by Thompson in the Blues penalty area handed the hosts a spot-kick.
And just minutes after coming on as a substitute, Lines fired home with 15 minutes remaining.
Pompey's response was to bring on Pitman for Hawkins.
And he was was quickly into the action - taking a boot to the face from Lines - who was subsequently shown a straight red card.
Pitman saw his effort from the resulting free-kick go well over, while Lowe fired into the side-netting moments later.
The game appeared destined to end in a draw - until Curtis' late intervention.
His shot goalwards hit the leg of Smith, who seemed to have done enough to prevent a goal.
However, the Irishman's effort still had plenty of velocity behind it and the ball was adjudged to have crossed the line.
MacGillivray then produced a top-class save to deny the hosts right at the death as Pompey hung on to claim three well-earned points.