Josh Scott came back from injury to come off the bench and rescue a late point for the Daggers.
With just a couple of minutes left on the clock and with Port Vale leading thanks to Louis Dodds strike, Scott latched onto a Mark Arber flick before clipping a classy finish over the goalkeeper to snatch what was probably a deserved point.
The draw left Dagenham and Redbridge a couple of points adrift of leaders Bournemouth, whilst it also maintained their unbeaten record at the London Borough of Barking and Dagenham Stadium.
John Still's side saw one change from another dramatic finish the previous week at Macclesfield. Loan signing Matt Lockwood came in to make his debut for the club.
One of Dagenham's more impressive performers, Stuart Thurgood, almost scored inside the first couple of minutes. Vale keeper Chris Martin didn't get any height on his clearance and the ball reached Thurgood. The midfielder volleyed the ball back immediately from the half way line only for his effort to roll wide.
Thurgood later jumped for a loose ball on the edge of the area. He reacted quick enough to strike first time but his shot failed to trouble the Port Vale keeper.
The Daggers did look like they were building some momentum early on in the game. Peter Gain shaped a volley that flew narrowly while Gareth Owen did well enough in the visitors defence to deflect Paul Benson's header over.
Scott Doe found Danny Green with a neat pass. Green in turn fired a shot that reached Wes Thomas, who wasn't able to direct the ball on target.
Jon Nurse drilled a low effort to the near post which was gathered by Martin but whilst the Daggers had the majority of the efforts early on, Port Vale were by no means overwhelmed.
Indeed after that Daggers spell, Vale started to exert some of their own authority and an early indication came after Kris Taylor shanked a volley well wide of goal.
The visitors were to get a lot closer with their next effort. Lewis Haldane was allowed to turn and shoot in the area before crashing a shot against the bar.
Mark Arber had to clear bravely with Marc Richards lurking inside the Daggers area.
Micky Adams' side were to take the lead with their next attack. Haldane played a low ball across the edge of the area. Dodds picked up the ball, cut inside and rifled a shot right into the top corner of Tony Roberts' net.
Green tried to respond to Port Vale's opener but his free-kick flew well over the bar.
The home side started the second half looking for an equaliser. It looked like Gain had got it for them with a curling shot that looked destined for the back of the net. A brilliant save from Martin however kept his side ahead.
Martin was in action again after Arber's long free-kick reached Benson. The striker turned and shot in an instant and was only denied by a good block from the Port Vale shotstopper.
Matt Lockwood hit a free-kick over but the visitors defence was keeping the Daggers at bay.
They also threatened on the break. A counter-attack saw Jason Jarrett fire into the Port Vale supporters. Kris Taylor meanwhile crossed for Dodds who saw his flicked header drift over.
With Daggers seemingly coming up against a Port Vale wall, John Still reacted by throwing on Scott, Graeme Montgomery and Harlee Dean from the bench.
Scott had an immediate chance to make an impact. He got in behind the defence from a Benson flick on but lacked the composure on his finish by striking well over with only Martin to beat.
Dean meanwhile was sent into an attacking position and he headed over from six yards after getting on the end of a Montgomery cross.
It was all Daggers at the end but with Montgomery flashing a volley across the face of goal all hope of a point looked lost. That was until Scott pounced.
Att: 2,003 (265 Port Vale)