The 31-year-old Reds captain and England international had not started a match since the side's 3-1 win against United in March as he has been sidelined with a groin injury which required surgery and then became infected.
However, following three substitute appearances, Gerrard started and scored against the Red Devils at Anfield on Saturday lunch-time. And, he was pleased that there was no adverse reaction to getting a full 90 minutes under his belt.
Gerrard told Liverpool's official website: "I'm stiff and tired, but that's to be expected. The physios and medical staff knew that (would happen).
"That's what I've got to do to push on and gain maximum fitness.
"I still need two or three 90s under my belt to get back to 100 per cent, but I am very pleased at how my groin held up and how my body felt for the first 90. Really pleased."