Farah had been tipped to challenge Eliud Kipchoge for the title but after running the first 30 kilometres in a British record time, he fell away in the latter stages.
He finished over three minutes behind Kenyan great Kipchoge, who won his fourth London Marathon in five years.
Farah's preparations were overshadowed by his public dispute with Gebrselassie, with the Briton unhappy that he did not receive help from Gebrselassie after he was robbed at a hotel in Addis Ababa owned by the Ethiopian.
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Sir Mo Farah finished in fifth, three minutes and one second off the winner

Image credit: Getty Images

Gebrselassie, a former world record holder and current president of the Ethiopian Athletics Federation, said the matter was immediately reported to police, who interviewed five hotel employees but decided not to bring charges against any of them.
The episode dominated the news in the run-up to the Sunday's race, but Farah said he retained his focus despite having failed to challenge for the lead throughout. Farah said:
I didn't think the fuss affected my run and I wasn't distracted by the build up. It was all about London today and so I put my head down, did my best.
"I don't regret anything I said and I respect the race.

Farah's build-up was overshadowed by a dispute with Haile Gebrselassie

Image credit: Getty Images

"My aim was to reel them back once the pacemaker dropped out but wasn't able to. I am disappointed as training went well."
Farah also said he is yet to decide which race he will commit to in the upcoming World Championships in Qatar, where he could compete in either the marathon or 10,000 metres.
"At the minute my brain is all over the place," he added. "I am going to have a chat with my coach and my agent and have a step back.
"I think for me I want to do a marathon. I gave it my all, I was aiming to run a low 2:04 but that is what it was."
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