The 25-year-old forward headed home Chris Herd's cross in the 29th minute to secure the Barclays Premier League club a second straight 1-0 success on their United States tour.
He departed in the second half after taking a knock, but Villa swiftly allayed concerns over the severity of the problem by posting on Twitter: "Gabby Agbonlahor injury not as bad as first feared. Out for two weeks."
England striker Darren Bent played no part due to a slight thigh strain.
Paul Lambert's side, who beat the Philadelphia Union on Wednesday, now head to Portland for a game on Tuesday.
Source: PA
Source: PA