Rotherham’s weaknesses in attack and defence and the lack of incisive power in the forwards are beginning to threaten the club’s Championship status.
This latest setback at Clifton Lane, where they were beaten by six tries to three, was the fourth consecutive league defeat, and sixth in succession in all competitions.
Rotherham’s decline has dropped them to ninth in the league and, bluntly, the Titans have landed themselves in deep trouble and are engaged in a survival battle alongside London Scottish, Ealing Trailfinders and Moseley.
With nine league games remaining, the players can forget about realising the ambition of reaching the promotion play-offs again. The target must be to stay in the Championship and avoid falling into National One.
Titans locks Toby Salmon and George Oram also suffered thumb injuries which will sideline them for several weeks.
At least Rotherham produced a determined reaction late in the second half as Pirates were cut to 14 men after forward Laurie McGlone was sin-binned.
Titans scored 21 points between the 65th and 74th minute as winger Michael Keating, full-back Sean Scanlon and second-row and captain Tom Holmes scored tries, all converted by replacement fly-half Ross Jones.
The Pirates forwards had dominated to set up five tries that provided a match-winning lead of 33-0 by 55 minutes.
Four of the tries, including three by prop Marlen Walker, were the result of Rotherham’s inability to defend a driving maul.
Pirates scored a sixth try in stoppage time through replacement No 8 Thomas Duncan.
Coach Mark Jones said: “You have to be positive because we finished strongly. How often do you lose when you score three good tries? But we simply can’t go on committing simple errors.”
Rotherham Titans: Scanlon, Keating, L Hayes, Barker, J Hayes, McKinney (Jones 59), Carter (White 53), Hislop (Cromie), C Maddison (Preece 62), Thiede (Tampin 40), Holmes, Salmon (Oram 37), B Maddison, Calladine (Birch 53), Argyle.
Cornish Pirates: T May(Riley 75), Arnott, Bodilly, Hendrickson, Evans, L May (Hallett 66) A Day (Townsend 74), Walker (Gendall 60), Channon (Innard 62), Paver, McGlone, Beukeboom, Parker, Atkinson (Lee 67) Carpenter (Duncan 48).
Referee: A Jackson (RFU).