However, the girls' players Rebekah Vardy and Shappi Khorsandi were hot on their heels heading in to the final stage.
They had an advantage in the 'water' challenge thanks to their comrades back in base camp, who triumphed in the 'earth' round.
Each team had five logs with small keys attached to them, one of which would unlock the final part of the flag they needed to summon a helicopter back to camp.
The catch was that the flag pieces were attached to a tree at the end of a fast-moving river.
The girls' advantage was that they only had five keys to try, while the boys had to work through ten keys to find the right one.
Dennis and Jamie were first to launch themselves in to the river, before the girls dived in, wearing their safety helmets and rucksacks.
This proved to be a setback for Shappi, who exclaimed: "My helmet is strangling me and I can’t see. I need help."
Her super-competitive partner Becky showed little sympathy, responding: "Stop talking and swim."
The pair further bickered when Becky asked Shappi what their instruction laminate said - but the comedian wasn't sure what one she meant.
Meanwhile, the boys had a stroke of luck. Despite having more keys to try, they picked the right one to release their flag part on their first attempt.
They soon had the flag stitched together and were first to call their return helicopter, meaning they'd won the feast.
Explaining what went wrong, Shappi said: "I couldn’t hear or see a thing, my helmet came over my eyes.
"Becky was shouting, 'what did it say', and I had no idea what she was talking about. I thought there was a scroll I’d missed.
"There was no tension, it was two women in a river with rucksacks on their backs. I was trying not to drown."
The boys were thrilled when Dennis and Jamie arrived back in Croc Creek with the news that they'd triumphed.
Becky and Shappi followed, with the former admitting that the result left her "f***ing fuming".
"Me and Becky deal with losing in very different ways, when I lose something I try to look at the positive side," explained Shappi.
However, Becky insisted there was "no hard feelings" and wished the boys a "lovely evening" as they made their way to the Snake Rock camp, where bosses had set up their feast.
They dined on lamb shank, roast chicken, potatoes, corn, salad and fruit, with an option of an alcoholic or fruit juice drink.
I'm A Celebrity 2017 airs nightly on ITV.