DNA tests have confirmed that Prometea, who was born in Italy on May 28, is genetically identical to her surrogate mother.
It comes just two months after researchers revealed they had cloned the first mule, leaving other groups racing towards the accolade of creating the first cloned horse.
The race was won by a team at the Laboratory of Reproductive Technology in Cremona, led by Cesare Galli, and is reported in the journal Nature.
It is now hoped that the horse-cloning technique can be used to produce identical copies of champion jumpers and show horses.
The scientists said they had shown it was possible to produce a full-term pregnancy in which the surrogate mother was also the nuclear donor.
To create Prometea, the team fused a skin cell taken from the Haflinger breed mother with an empty equine egg.
During the process hundreds of embryos were created, some using cells from a male horse, leading to four pregnancies detected by ultrasound after 21 days in the mother.
Only one survived full-term and Prometea was born naturally 336 days later, weighing 36kg the only one of 328 reconstructed embryos to make it.
"Remarkably, this cloned foal was born from the same Haflinger mare who was the original cell-line donor," the researchers noted.
The team said Prometea's birth added the horse to the list of mammals which have already been successfully cloned.
Dolly the Sheep, created by scientists at the Roslin Institute in Edinburgh, was the first mammal ever to be cloned from a single adult cell.
The Italian team concluded: "Cloning could enable gelding champions to contribute their genotype to future generations, as well as opening up an opportunity to verify the reproducibility of traits such as character and sporting performance."
Gordon Woods, who led the University of Idaho mule-cloning team, said the successes in cloning equines could open the door to cloning racing champions, or horses with other sought-after traits.
For example, Funny Cide, the winner of both this year's Kentucky Derby, is a gelding, or a castrated male. Cloning him would keep his champion genes in play.
"If one could clone Funny Cide, the clone of him could be the stud. He could pass on the genetics," Mr Woods said.
Philip Freedman, chairman of the British Thoroughbred Breeders Association, said the development was of "no value" to the racing community because horses created by artificial insemination could not enter world racing stud books.
Mr Freedman said it would be a "retrograde step" to allow such technology to be used in racing.