Plymouth top scorer Reuben Reid took his tally to five goals in six games as John Sheridan's Pilgrims beat 10-man Southend 2-0 at Home Park.
The hosts took a 52nd minute lead when attacking midfielder Lewis Alessandra picked his spot with a side foot finish from 10 yards following Kelvin Mellor's mazy run and cutback from the right.
Mellor and Alessandra combined down the right to tee up striker Reid to head home from eight yards out on 67 minutes.
Plymouth right back Mellor cleared off the line to deny Southend striker Barry Corr as he swooped at the far post to convert Myles Weston's cross from the right in the eighth minute.
Southend were forced to change their line-up on 15 minutes when central defender Cian Bolger was dismissed for a second bookable offence for fouling Plymouth target man Marcus Morgan. Bolger had been cautioned for a foul on Morgan in the opening minutes.
In first half stoppage time Carl McHugh's free kick from the right was headed just wide by Plymouth Reid.
Plymouth made better of their one-man advantage in the second half with Southend keeper Daniel Bentley forced to make a brilliant full length diving save to push McHugh's goal-bound header wide.