IT was a day of tears and prayers for the parents of Tia Pugh as the tiny toddler faced her bone marrow transplant.
Her father Nick, from Bath Road, Worcester, said the three-year-old, who is battling two extremely rare immune diseases, is tired but still playful after Tuesday's transplant.
Tia had the surgery at The Great North Children's Hospice, Newcastle, after a worldwide search for a donor was launched in February.
The little girl and her parents pushed the button which started the procedure together and now it is a case of waiting to see if the transplant improves her health.
Doctors have been baffled by Tia's symptoms but believe she may have STAT-1 deficiency and a tuberculosis-type disease called Mycobacterium malmoense.
It is possible that she is the only person in the world to suffer from both diseases simultaneously and experts believe the transplant is her only hope.
Mr Pugh said: "The transplant went well.
"They have special zones of danger and when they improve you move out of that colour zone.
"We are in the red zone which is the danger zone.
"It's still early days though and dramatic changes can happen anytime.
"I felt a bit tearful pressing the button and we've been told to closely watch Tia for any dramatic changes which can be normal in some cases.
"We feel petrified and nervous but we know this is Tia's only chance and we're praying it works."
The brave girl has shown no side effects so far other than being tired and daydreaming.
"I have tried pulling funny faces to get her to smile but we will only get the occasional a grin but she is very alert."
Despite this, tiny Tia has still managed to put a smile on nurses' faces by waving her arms and trying to dance to the Disney song Let It Go from the hit film Frozen.
A worldwide search was launched to find a donor for Tia because of her mixed heritage - her father is British and her mother Yupa is Thai with Cambodian heritage.
Tia and her family have not been told the identity of the donor.
Mr Pugh has been keeping followers up to date with the transplant on the Facebook page Tia Pugh Immune Deficiency.