After Joao Pedro had Chelsea 1-0 ahead at halftime on Saturday night, Watkins struck twice as Villa stormed back to win 2-1.
“Amazing, amazing win,” he said post-match.
“Obviously, for me personally, to come on and score two goals is a great feeling.
“But to keep up this run and to come away here and beat Chelsea at a tough place is amazing – it’s the word to sum it up, really.”
On manager Unai Emery's changes, Watkins also said: "He changed it because Chelsea were going man for man, but they had the extra centre-back when we were going long.
“So, when I came on in the second half, he brought (Jadon) Sancho on the wing and Morgan (Rogers), and I think it gave us a little bit more space.
“And then put Youri (Tielemans) in the No.10, so we had an extra body up there.
“Tactical genius, I would say.”