The hosts belied their position towards the bottom of the table and led the Titans for much of the first half with the Yorkshire side scoring tries through wing forward Eruini Wano, second row Jamie Ure and No 8 Sebastian Nagle-Taylor.
Alex Dolly kicked two conversions to help them to a 19-15 lead.
Centre Ellis Abrahams kicked a penalty on the hour mark to put Rotherham 22-15 ahead, but a try with four minutes remaining put Bishop’s Stortford within reach of a draw – but the crucial conversion was missed.
Hull Ionians remain top of the National Two North table after scraping a late 18-16 victory at home against Macclesfield.
The Yorkshire side took an early lead with a sixth-minute drop goal by fly-half Morgan Bunting, and outside centre Lewis Minikin kicked a penalty in the 12 minute.
However, Macclesfield scored three tries with no response from the home side to leave the score 16-6 going into the final 10 minutes.
Substitute Sam Rees started the comeback in the 79th minute when he crashed over before Minikin converted to leave the score 16-13 with one minute to play.
Minikin then crashed over deep in added time to snatch a late victory and seal the points for Ionians.
Elsewhere, Wharfedale secured an 18-3 win at home to Tynedale.
Fly-half Jack Blakeney-Edwards gave the home side the lead in the 15th minute with a penalty before Wharfedale were awarded a penalty try in the 20th to make the score 10-0.
Blakeney-Edwards added a second penalty in the 40th minute before scrum-half Sam Gaudie scored the only try of the game in the 50th minute to secure the win.
Otley won 14-13 at South Leicester. Outside centre Stephen Nolson gave them the lead with a try in the 20th minute before South Leicester hit back on 28 minutes with a try of their own.
Centre Declan Dunn regained the lead for the away side in the 54th with a try that was converted by fly-half Ben Smith, and Otley held out to seal the victory after a late fightback from South Leicester.
A last-minute penalty saw Huddersfield scrape a 20-20 draw at Fylde.
The home side took the lead in the first minute with a converted try before prop Alex Battye crashed over for the away side.
Fly-half Chris Johnson scored a second try for Huddersfield in the 19th minute to take the lead before adding a penalty to his points tally in the 40th minute.
Fylde hit back with a converted try and a penalty to leave the score at 20-17 going into the final minute as Johnson held his nerve to kick a penalty and snatch a share of the spoils for Huddersfield.
Hull remain top of the North Premier division as they won 49-7 at home to Billingham.
Harrogate were also victorious, winning 24-17 at Ilkley to secure maximum points having scored four tries.
Scarborough moved to the top of North One East after winning 41-26 at home to Malton and Norton, while previous leaders Huddersfield YMCA dropped to second having lost 12-12 at home to Morley.
In Yorkshire One top of the table Moortown did just enough to preserve their lead, winning 25-24 at Pontefract.
Second-placed Heath took a maximum five points from a 32-8 win over Keighley, while Old Crossleyans are level with them on points following an 18-17 win at Bradford Salem.