The final of the highly-rated cooking show aired tonight on BBC Two.
The two judges, Michelin-starred chef Michel Roux Jr and celebrity grocer Gregg Wallace, were unable to choose between Keri Moss and Anton Piotrowski.
Roux Jr said: "This has probably been one of the hardest, tightest finals that I have ever seen.
"It was just impossible to split them - their talents have been matched plate for plate for the past several challenges and it was truly impossible to award one the title over the other."
Wallace added: "What an amazing final, I can't ever remember a decision this tight."
[MasterChef judges Monica Galetti, Michel Roux Jr and Gregg Wallace]
Moss said of the shared win: "Joint winners is just fantastic, we've had a good run together, Anton is awesome."
Piotrowski agreed, saying: "It's absolutely amazing; to share the title with someone that's so talented and so amazing is unreal. It's a good start to the rest of my life, mind blowing!"
The two chefs, along with fellow finalist Oli Boon, earlier took on a service at Heston Blumenthal's three Michelin-starred restaurant The Fat Duck, where they cooked some of Blumenthal's most-celebrated dishes for guests and the judges.
MasterChef has proved a huge hit on both sides of the Atlantic, with the recent US adaptation beating America's Got Talent in the ratings.