Prime Minister Manmohan Singh, who is today undergoing a complex heart bypass surgery in a premier hospital here, had a successful first graft and two more similar procedures were to be performed, doctors said.

The first graft has been successfully performed on the Prime Minister at 3.10 pm in AIIMS, Sudhir Vaishnav, cardio-vascular thoracic surgeon with the AsianHeart Institute (ASI), Mumbai, said nearly eight hours after the operation began this morning.