The attacker grabbed her and forced her into bushes as she ran in Goodmayes Park, close to her home, at 2.30pm on Monday.
The suspect is described as a white male, approximately 17-20 years of age, around 6ft tall with straight blonde hair and a slight moustache.
He was wearing blue tracksuit bottoms and a long black jacket and struck near the basketball courts in the park.
The victim is being supported by specially trained officers and police have stepped up patrols in the area.
There have been no arrests and officers are hunting the suspect.
Detective Constable Gemma Morris from the East Area Command Unit, said: “Goodmayes Park would have been busy at the time of the afternoon and I am appealing to anyone that was in the park and saw the male described to please come forward and provide us with information. No matter how small or insignificant you think your information might be, it could really help our investigation.”
Please get in contact with us via 101 or tweet MetCC and quote CAD5395/1Feb. Alternatively, call the independent charity Crimestoppers anonymously on 0800 555 111.
