But Pirates had the bench depth and overcame their execution flaws and discipline issues to control the ball in the final quarter, pounding Border's line on the back of a growing penalty count, before promising second-five Vaovasa Afasua finally dashed in at the far corner and was ruled to be not held when he climbed up from the cover tackle to dive again and score.
Halfback Fa'alele Iosua could not add the difficult extras, while Border still had a chance to steal the game when Dabenaise and Harding nearly put winger Tom Symes away to score, and although their team received a penalty, Harding left his kick outside of the nearest post with time up on the clock.
Referee Kawana Tihema sinbinned Pirates first-five Denning Tyrell (late tackle) and Border's Angus Middleton (repeated infringements) near the start and finish of the first half respectively, but neither team could capitalise on their extra-man advantage.
"Probably a fair score, no-one took the game by the scruff of the neck," said Border coach Justin Lock.
"Quite disappointed in our option taking.
"Their boys are big and put you under pressure."
Picking up two competition points, which now leaves them in a three-way tie from third to fifth on the Premier table, Pirates coach Phillip Morris acknowledged that other than the excitment of the scoreline it had not been a quality match.
"We had enough strike ball in the first half to win two games. Just lacked composure.
"The foundation is there.
"It would be nice to get past 4-5 phases.
"But white line fever...using that energy, mistakes can happen."
In a game with few standouts, Pirates forwards Raymond Epati, Siulagi Lafi and Fa'amanu Manutulila took plenty of hit-ups and were resolute on defence, while Afasua will prove another welcome addition to the island imports.
Border's veteran flanker Ray Stark gave a determined 80 minute effort, while Dabenaise and Harding look dangerous every time they get together.
Pirates struggled to clear the kickoff from their half and were caught up offside for Harding to take the penalty.
However, the visitors then struggled to find touch on their own clearances as Manutulila, flanker Tafulu Isaako and No8 Lasa Ulukuta ran hard on the fringes to put their team on attack, as Afasua broke through the line before the ball was transferred wide for Tyrell to score in the corner.
Despite losing Tyrell for taking down Border first-five Grayson Tihema, Pirates maintained control of the territory, with Ainea sweeping through before Harding made a try-saving tackle on winger Romeo Tiatia, but Pirates got a penalty to make it 8-3 after 17 minutes.
Shortly afterwards, Manutulila beat his man and fed Tyrell in space, finding Epati who despite stumbling was able to keep his feet and dive over for 13-3.
Pirates stayed camped in Border's half but over-extended after flanker Tafulu Isaako's burst and from the turnover, Dabenaise put Harding free out wide, with quick winger Tom Symes sweeping up his chip kick for the ball to be transferred left back to Harding to score in the corner.
With instructions from the sideline to use the width, Border regained the lead in the 53rd minute after Pirates spilled an attacking chip kick in the corner, and from the scrum the passes beat the defenders for Harding to glide through and hold off his opposite Tupu Ulufale to score and then convert.
Harding added another good penalty kick five minutes later for 18-13, but Pirates found another gear as Manutulila attacked the line, despite getting collared high, while Afasua nearly broke through.
Choosing a succession of penalty scrums, Pirates kept up the pounding until they shifted wide, where Afasua took the long pass and charged at the corner, landing short in the tackle but going again to plant the ball, which was ruled acceptable by the officials, to set up a tense final five minutes.
Border 18 (N Harding 2 tries; Harding 2 pen, con) drew with Pirates 18 (D Tyrell, E Epati, V Afasua tries; J Ainea pen). HT: 13-8 Pirates.