Spoiler alert! The Bachelor ending shown during promo

AN UNFORTUNATE promo stuff-up has infuriated a bunch of The Bachelor’s loyal viewers, for whom last night’s episode was well and truly spoiled.

AN UNFORTUNATE promo stuff-up has resulted in The Bachelor’s regional viewers knowing the result well before the penultimate episode ended.

Network Ten’s regional affiliate Southern Cross made the error on Wednesday night when it aired previews of Thursday’s finale, showing the two finalists, well before the rose ceremony.

It’s the second time this year the regional network has angered Ten’s viewers.

Southern Cross, which takes programming from Ten but schedules its own ads, made the same mistake with MasterChef.

“We can confirm that Southern Cross made a technical error tonight which they are looking into,” a Ten spokeswoman told AAP.

Viewers from Tasmania, Newcastle and Canberra vented at Ten but their anger should have been aimed squarely at Southern Cross.

“What is with channel 10 spoiling sh*t, first Masterchef, now #TheBachelorAU you people are f***ing useless,” tweeted Kylar.

Jacqueline Maree wrote to Bachelor host Osher Gunsberg for help, “oshergunsberg CAN YOU TELL THE PEOPLE THERE TO GET THE DAMN ADS RIGHT !???? #TheBachelorAU #seriouslyten? #spoiler.

Robbie Macaulay posted, “Nice work on the finale ad there @channelten @TheBachelorAU ... Before tonight’s rose ceremony. Smooth. #thebachelorAU #mywifemademewatchit.”

There were others who said they were changing channels because of the massive error.

“Since the promo spoiled the result, off I go to #celebrityapprenticeau sorry #thebachelorau,” wrote Shannon.

Good one @Ten_Corporate you ruined another bachelor final with promo of finalists #thebatchelorau

— Michael Pegum (@mike_p_p) September 16, 2015

I'm confused, what day is it? @channelten promo is saying 'Bachelor Finale Next' I hope they play tomorrow's ep instead lol #TheBachelorAU

— Nicolle (@NicolleM88) September 16, 2015

Southern Cross has been contacted for comment.

For the record, for anyone who didn’t see the ads or the result, intruder Lana Jeavons-Fellows and single mum Snezana Markoski are the last two lonely hearts left standing.

Sarah Mackay was eliminated.

Sam will give his leading lady the final rose tonight.