Both sides finished the game with 10 men as Hereford earned a point at struggling Plymouth.
Tom Barkhuizen gave the Bulls the lead when he latched on to Harry Pell's pass to slot in from close range.
But Nicky Featherstone's foul on Warren Feeney allowed Nick Chadwick to crash home from the penalty spot.
Hereford were then reduced to 10 when Michael Townsend received his second yellow before Argyle's Darren Purse saw red for a foul on Nathan Elder.
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Plymouth boss Carl Fletcher told BBC Radio Devon:
"At times the first half was OK. At times we weren't. It was up and down.
"After going a goal behind we came back well and poissibly could have won it.
"In terms of what we're looking at and what we want it wasn't fully there today."
Hereford boss Jamie Pitman told BBC Hereford & Worcester:
"We go into every game wanting to win it but obviously it was a big game given where both teams are in the league.
"Our last three performances previous to this one have not given us the rewards we have probably deserved.
"Today was another such case. To be fair to them they have had a few chances but I think we were good value for the win."
Plymouth Argyle 23 Cole 02 Berry 05 Purse Dismissed 22 Blanchard 03 Williams Booked 08 Walton (Young - 70' ) 20 Hourihane Booked 21 Atkinson 10 Sutherland (Feeney - 58' ) 29 Chadwick 31 Hemmings Substitutes 01 Larrieu 07 Daley 13 Soukouna 15 Young 11 Feeney Hereford 01 Bartlett 05 Townsend Dismissed after an earlier booking 20 Dalibard Booked 04 Pell 06 Purdie 07 Leslie (Colbeck - 64' ) 08 Featherstone 18 Clist 09 Arquin (Elder - 79' ) 10 Facey 21 Barkh'zen (Clucas - 90' ) Substitutes 29 Hanford 17 Colbeck 27 Clucas 25 Elder 26 Peniket