Andy Bond was on target for the U's again on Saturday, but they had to make do with a share of the spoils for the third time at home this season as Plymouth grabbed a goal just after half time.
The U's were again left to rue not getting their second goal when in the ascendancy, but the Pilgrims were much improved after a poor first half display.
The result keeps the U's in the thick of the sides at the top of the table, but they know that they will need to start winning games at home to keep up the pace.
The U's started the earliest stages of game on the front foot, but Argyle responded well, and Okuonghae had to be quickly across to take it off the toes of Parrett as it looked like the midfielder might burst through.
Chances were at a premium in the early stages, with Bhasera's offside effort - well saved by Cousins - the only chance of note in the first ten minutes.
The U's had to make their first change of the game with only fifteen minutes on the clock. Wilson had picked up an ankle injury early on and had to be replaced by White.
It was the other full back Tierney who had the U's first effort, stepping onto a free kcik and driving in an effort that the keeper pushed away from danger.
Then, from another free kick, Vincent's shot on the angle saw the keeper save before forcing it away a second time as the winger followed up.
The U's were starting to see a few sights of goal, as they looked to try and click into gear with the mid-point of the first half arriving.
And they got their noses in front on 22 minutes as that man Andy Bond grabbed his fourth of the season, powering home a header from a corner despite the efforts of Button.
Two minutes later and they were inches away from a second. The ball was well worked into the path of Wordsworth and he curled an effort that went inches past the far post with Button beaten.
The U's were well on top at this stage and needed that second goal that their efforts warranted to give them a cushion in the match.
Another corner flew across the face of goal, before a cleverly worked corner to the edge of the box found Perkins, whose goalbound shot hit his own man Baldwin on the way through.
On the half hour mark, good play from Mooney was inches from getting Wordsworth away, but Button was quick off his line to intercept on the edge of the box.
Molyneux went into the book on minutes for blocking Izzet taking a quick free kick, with the U's captain having burst away down the left.
Argyle were struggling with their ball retention, losing the ball regularly in midfield, and allowing the U's to break.
The U's hit the visitors on the break five minutes before the break as Vincent took the ball forwards, passing it onto Wordsworth.
He in turn sent it onto Mooney and, with the Irishman having more time than perhaps he thought, he scuffed his shot wide of the post.
Parrett went into the book a minute earlier, kicking the ball away in frustration after he knocked the ball out of play with some poor control.
The U's had to stay strong defensively as the half came to a close, and got to the break with the advantage.
As they sought a path into the game, Noone was introduced during the interval for Parrett. And a long ball over the top almost got Fletcher in, but Cousins just about got to the ball to clear it away.
But the U's keeper could do nothing about the resultant throw in and cross into the box, as the ball dropped in the danger area and Johnson lashed home with Cousins getting a hand to it before it crept in.
Two minutes later, Vincent flashed a header wide of goal as he beat his man to the ball, but the linesman's flag was up for offside.
Bhasera went into the book for a foul on White, although it looked harsh as the U's man went to clear the ball.
The U's went back on the offensive, with Vincent using his pace to skip past his man and send over a dangerous cross that was just past the awaiting Mooney at the far post.
Argyle had been enlivened by their goal, though, and Arnason stepped up to drive a shot just beyond the far upright on 58 minutes as Cousins watched on.
Going the other way, Bond stepped onto an Argyle mistake to try and get Mooney away, but just over cooked his pass.
The visitors were forced into a change with half an hour left, as Button failed to shake off an injury and was replaced by the experienced Larrieu.
The U's had shook off the initial Argyle storm after their goal and were looking to turn the game in their favour.
Mooney was then fouled by Timar down the right but, much to the U's fans amazement, nothing was given. The Argyle fans had been aggrieved by their treatment by the officials in the first half, and were at least happy to see that decision.
The game had a niggly undertone, but Perkins was unlucky to go into the book for a foul on Arnason, with the referee seemingly only reacting after encouragement by the visiting players.
As Argyle broke on 70 minutes, Noone was put in down the right, but chose the wrong option as he smashed a shot at Cousins with men waiting in behind.
The U's made their first change shortly after that, with Odejayi coming on for Mooney for the final twenty minutes of the game.
The substitute had only been on for a matter of seconds when Vincent beat his man to whip in a low cross that the striker missed as it came in at the near post.
And they were inches away again on 74 minutes as Odejayi sent Perkins away, he skipped down to the byline and sent over a cross that Wordsworth was agonisingly close to at the far post.
Arnason then went into the book for a late tackle on Wordsworth, before Argyle introduced Paterson for Bhasera for the last ten minutes of the match.
The visitors were reduced to ten men for the last seven minutes of the game, with Molyneux booked for a second time as he held back Perkins as the U's looked to break.
Bond smashed a shot wide before Izzet and Baldwin became the latest players to be booked, as the referee continued his influence on the game.
The officials were causing consternation on both sides, and the four minutes of additional time seemed short given the injuries and stoppages that had preceded its announcement.
Vincent was in the right place at the right time to clear at the back post with Noone lingering with intent.
But the match was to end all square as the U's were left to rue another lead slipped.