It all went down Thursday morning -- when Phil's wife was playing tennis with a family friend. We're told the man suddenly became disoriented -- collapsed -- and started to go "in and out of consciousness."
We're told Phil's wife Robin screamed for the doc to call 911 -- which he did -- and while on the phone with the dispatcher, Phil raced over to the court to tend to his friend.
Sources close to the McGraws tells us Phil checked the man's pulse and calmly relayed all sorts of important information to paramedics as they raced to Phil's pad.
The man was transported to a nearby hospital -- and was released a short time time later. We're told he's "doing fine."
It pays to have a (TV) doctor in the house.