The Yorkshire side took the lead in the first minute as winger Daniel Leake crashed over, before Sam Hollingworth successfully kicked the conversion and added a penalty to leave the score 10-0 after 10 minutes.
Plymouth went on to level the scores before Hollingworth added another penalty and scrum-half Sam Boxhall added a converted try to regain the lead for the Titans.
But the Devon outfit then went on to dominate proceedings adding four converted tries with no reply from Rotherham.
Flanker Zak Poole and winger James Cooke both crashed over late on to secure two bonus points for the home side, which may be vital in their fight against the drop.
Hull Ionians slumped to a heavy 54-7 defeat at home against Chinnor.
Ionians took the lead when winger Jack Colbourne crashed over in the 20th minute and fly-half Max Titchener successfully kicked the conversion to leave the score 7-0.
But the away side went on to score eight tries with no response, which leaves Ionians second bottom in the table, a place below the Titans.
After trailing for the first hour, Otley hit back to take a 16-13 victory over Tynedale and leapfrog them in the National Two (North) table.
The visitors took the lead in the 10th minute with winger Seamus Hutton touching down for a converted try, but fly-half Ben Smith successfully kicked two penalties for Otley to leave the score 10-6 at half time. The away side added another penalty to their tally early in the second half before full-back Ben Magee and outside centre Elliot Morgan crashed over to secure the points for Otley.
Elsewhere, Wharfedale had to settle for a losing bonus point after battling well at high-flying Fylde on losing out 24-17.
Jack Blakeney-Edwards’s first half penalty was their only score of the first 40 minutes, but Wharfedale ran in two quality tries after the break.
Matt Speres crossed after good work from Oli Cicognini who had danced through a packed Fylde defence, and Blakeney-Edwards added the conversion.
And he also added the extras following a later try from Cicognini after a break from Ben Blackwell. But despite pressing hard for further points Wharfedale had to settle for one point when a draw might’ve been a fairer result.
Sheffield Tigers slumped to a 40-7 defeat away at Caldy. A last-minute converted try from fly-half Mark Ireland was nothing more than a consolation for the Yorkshire side who are now sixth in the table.
Trailing 25-3 with ten minutes left, Hull battled back to secure a losing bonus from a 25-18 defeat at home against Stourbridge.
Replacement Alex Heard and flanker Thomas O’Donnell both crashed over late in the game to bring the score to within seven to secure a bonus point for Hull.
Stand-off Tom Foster’s 35th- minute try and the conversion from full-back Paul Cook put Scunthorpe into a 7-3 lead at home against Preston Grasshoppers. But from then on it was all one-way traffic and the Lancashire side went on to win 30-7.
Harrogate beat hosts Kirkby Lonsdale 30-16 to close the gap at the top of the North Premier table to five points.
Leaders Billingham lost out 35-26 at Sandal, while Ilkley were also victorious beating visitors Carlisle 32-29.
York are top of the North One East table after beating hosts Morley 53-23, while Driffield dropped to second after struggling to a 15-15 draw with Durham City.
Cleckheaton’s big 47-14 win over Percy Park sees them overtake Morley and move up into third place.