Billy Clarke came off the bench to score on his Grimsby Town debut but the Mariners had to settle for just one point against Leyton Orient at Brisbane Road.
The hosts had created the better chances in the first half but were unable to force a breakthrough as Town defended well.
And after Clarke was sent on, he broke the deadlock with his first opportunity to put the visitors ahead to the delight of their 1,200-plus travelling supporters.
But they were not quite able to hold on for a third consecutive victory as the hosts struck back from the penalty spot in added time, with Lee Angol stepping up to rescue a point from 12 yards.
Four changes were made to the Town starting XI after the win at Mansfield, with new signing Anthony Glennon making his debut in place of Liam Gibson at left-back as fellow new boy Clarke had to be content with a place on the bench.
Mattie Pollock came in for the suspended Luke Waterfall, while Elliott Whitehouse was the man to replace Ethan Robson after he returned to Sunderland and Ahkeem Rose came into the side in place of Moses Ogbu.
James McKeown started in goal, with Luke Hendrie, Harry Davis, Pollock and Glennon in defence.
Harry Clifton, Jake Hessenthaler and Whitehouse were the midfielders, with Max Wright, Rose and Charles Vernam in attack.
The substitutes were Sam Russell, Ludvig Ohman, Brandon Buckley, Elliott Hewitt, Clarke and Harry Cardwell.
Orient came into the game looking to complete a league double over the Mariners, having won the reverse fixture 4-0 at Blundell Park.
The hosts won the first corner of the game a minute in through Angol on the left but it caused no problems as the ball from the flag was headed wide by Dan Happe.
Another corner came on nine minutes when a cross was headed out by Glennon. This time, the ball from it was cleared by Davis.
A foul by Davis on Angol gave the home side a free kick in a dangerous position but Jordan Maguire-Drew's shot from it was deflected away for another corner, which was cleared off the line by Wright after McKeown's punch hit an attacker.
Whitehouse got the ball out for another corner on 13 minutes and before it was taken, Town were forced into making the first substitution as Davis, still feeling the effects of his challenge on Angol, was replaced by Ohman.
A good chance came on 17 minutes when Maguire-Drew turned and shot but the ball was turned over the bar by Angol from close range.
Better signs for the Mariners came with a run through the middle by Vernam which was eventually stopped when he was fouled by Jamie Turley. The defender picked up an injury in the challenge and had to go off, to be replaced by Myles Judd.
A foul by Pollock on Conor Wilkinson on 27 minutes gave Orient a free kick on the right but the ball into the box was headed away and the clearance was completed by Clifton.
Hessenthaler was shown the first yellow card of the game two minutes later after a late challenge on George Marsh but the resulting free-kick was dealt with by Ohman.
Town's first corner came just after the half-hour and they retained possession after Hessenthaler's ball was only half-cleared but after it was worked back into the penalty area, Hessenthaler's header went through to home keeper Sam Sargeant.
Another free-kick at the other end caused no problems, before Whitehouse won a corner for the Mariners soon afterwards. Hessenthaler's ball was headed away, then the referee's whistle blew for a foul by Pollock.
A shot by Rose was blocked and Whitehouse was fouled as he chased the ball down, giving Town a free kick on the left. Hessenthaler's ball from it was half-cleared and the ball dropped for Whitehouse, who sent it wide of the target.
Hendrie made a run into the box on 40 minutes after a good move involving Pollock and Hessenthaler, although the right-back's shot from a narrow-angle was blocked by Sargeant at the near post and the ball ricocheted back off Hendrie for a goal kick.
The hosts won a corner after a cross hit Glennon in the face and the ball went out of play. The ball from the flag curled over the bar for a goal kick.
Three added minutes were played at the end of the first half and Angol headed wide in the first of them.
That proved to be the last opportunity before half-time, with Orient having the best chances but Town defending well.
No further changes were made before the restart and an early Mariners free-kick came when Wright was fouled by Judd. The ball from it was cleared.
Whitehouse missed the target with a shot from close range on 49 minutes, then a foul on the midfielder two minutes later brought a free-kick and earned Hector Kyprianou a booking.
Vernam won a corner when his cross was blocked on 52 minutes and it eventually led to another one. This time, Hessenthaler's driven delivery was turned back across goal by Rose at the far post but Wright could only send it over the bar.
A cross by Wilkinson was turned away for a corner by McKeown on 57 minutes, with the keeper then catching the ball from the flag.
Angol was booked after he fouled Clifton on the hour and soon afterwards, Clarke was sent on for his Grimsby debut as Rose made way.
A Town corner came on 64 minutes and it led to Clarke hitting a first-time shot but the ball bounced off Ohman and went through to keeper Sargeant.
Former Mariners midfielder Craig Clay was sent on in place of Kyprianou for the hosts a minute later, before McKeown was called into action to make a great save with his feet from Wilkinson, who got up to meet a cross and head it towards goal.
Hendrie did well to block a cross from Maguire-Drew for a corner, which went through to McKeown as the hosts continued to push forward.
Wright won a corner at the other end soon afterwards but Ohman's left-footed volley went over the bar after the defender had met the ball at the far post.
And the next time the Mariners attacked, they took the lead. A quick break saw Whitehouse play the ball through for CLARKE and he confidently lifted it over the onrushing Sargeant to make it 1-0.
The hosts immediately went in search of an equaliser and a corner led to another one when Wright got the ball away, with McKeown punching clear this time.
Ex-Town loanee Matt Harrold came on in place of Marsh for the home side with nine minutes to go.
Hendrie was yellow-carded for a foul on James Brophy on 83 minutes but the resulting free kick came to nothing.
Another free-kick came on 86 minutes when Clarke fouled Clay but again, Town survived as Happe shot wide after the ball had been played into the box.
McKeown was booked for time-wasting as he looked to run the clock down with the Mariners closing in on all three points.
But after five minutes of added time was signalled, the home side got their equaliser in the second of them. Clarke brought Clay down inside the box and after the referee pointed to the spot, ANGOL stepped up to beat McKeown.
Orient poured forward in search of an unlikely winner, with Wilkinson heading over the bar after a cross from Judd.
A foul on Clarke by Brophy then gave Town one last chance to snatch their lead back but after the defender was booked, Clarke could only hit the home defensive wall with his shot.
That proved to be the last opportunity for either side, with both forced to settle for just one point.
Town are next in action on Saturday, when Exeter City are the visitors to Blundell Park.
Leyton Orient: Sargeant, Turley, Brophy, Coulson (C), Happe, Kyprianou, Wilkinson, Wright, Marsh, Maguire-Drew, Angol.
Subs: Janata, Ekpiteta, Judd, Clay, Dayton, Harrold, Sotiriou.
Town: McKeown (c), Hendrie, Davis, Pollock, Glennon, Whitehouse, Hessenthaler, Clifton, Rose, Vernam, Wright.
Subs: Russell, Öhman, Starbuck, Buckley, Hewitt, Clarke, Cardwell.
Attendance: 6,248 (1276)
Referee: Will Finnie
Possession: Leyton Orient 55%-45% Town
Next Up: Exeter City (H)