The two sides were evenly matched and entered the break level as Phoebie Poole gave the visitors the lead after 18 minutes, before Kelci Bowers headed home four minutes later.
The second half continued in the same manner as the first, with both sides having good spells, but it was the visitors who won it at the death as Una Lue tapped home in stoppage time to see Argyle win 2-1.
That sees the Cherries drop six points behind the Devon side, meaning they will have to win their two games in hand to close that gap.
With six days left before these sides meet again in the National League Cup final, it was an even first half in front of a good crowd at the Ringwood Community Hub.
AFC Bournemouth vs Plymouth Argyle. (Image: Newsquest)
Plymouth had an early spell of territory but weren’t able to craft any openings, with the first chance of the match falling the way of the hosts.
Ex-Pilgrim Georgia Wilson drove into the box down the Cherries right in the tenth minute and had a go at goal but her effort went into the side netting.
Bournemouth went close again when Kenni Thompson delivered a superb ball from the left, but Bowers couldn’t divert her header on target and it went over the bar.
Moments later, the visitors took the lead.
Poole was played through on goal by Roisin Kivel and showed a cool head to finish calmly past the onrushing Katie Scadding to hand Argyle the advantage in the 18th minute.
Kelci Bowers drew the Cherries level. (Image: Newsquest)
But the home side were level four minutes later.
Awarded a free kick on the right, Katie James picked out Bowers whose looped header from the centre of the box dropped past Hermione Cull to equalise at 1-1.
It was an even contest with chances at a premium but the Cherries had two good chances in quick succession around the 35-minute mark.
The first saw Thompson pick the pocket of the defender but her squared ball for Quirk, who would have had a tap-in to an empty net, was swept up and cleared from the six-yard box.
Moments later, Quirk danced into the box on the left and delivered a good ball to the far post but Bowers couldn’t reach it and it went behind.
Sophie Quirk. (Image: Newsquest)
Poole again went in on goal four minutes before the break, but, under pressure from Charlotte Harris, she couldn’t get a clean shot away and Scadding made a good save to keep it at 1-1.
Plymouth missed a superb opportunity to head into the interval with the lead with the final play of the half.
Laya Proctor’s volley was well-saved by Scadding, but it fell to Ellie Noble in the six-yard box. She couldn’t hit it cleanly and her scuffed effort dropped back to Proctor, but she couldn’t hit the target and fired over from close range.
The game continued to be an arm wrestle in the early stages of the second half, .
The first shot on goal came 12 minutes into the second period when Quirk had a go from the angle on the left, but it was comfortable for Cull to catch at her near post.
Sophie Quirk. (Image: Newsquest)
As the game began to open up, the Cherries began to create more openings and enjoyed a good spell of pressure on their visitors.
Jenna Markham tested Cull with an overhead kick after Bowers headed down an Amber Treweek cross in the six-yard box, before Quirk shot just wide after a good solo run.
Bowers shot wide after cutting in from the right, before Helen Bleazard went to her bench, Elena Cole replaced by Molly Barron-Clarke with 20 minutes to play.
A neat move from Bournemouth saw a Thompson effort blocked behind as they sought the lead.
Kenni Thompson. (Image: Newsquest)
Plymouth, though, continued to carry a threat and had a good spell with 15 minutes to play, which saw Poole have two efforts from range blocked at the back.
Jessica Hennessy then made a superb block to clear the ball off the line from a Paris Dalton shot.
James was replaced by Phoebe Williams with ten minutes to play, before Thompson made way for Sophia Leonard.
Poole had another effort from range comfortably saved by Scadding after she found a pocket of space with the game ticking towards the close.
Plymouth found the winner in the second added minute when Tamara Wilcock let fly from range, Scadding saved superbly onto the crossbar but Lue was following up to tap home and send the travelling Argyle squad and fans wild.
The Cherries were unable to create a final chance to draw themselves level and, while they stay third in the table, they know they must win their two games in hand to close the gap on Plymouth.