It was also the quickest goal ever scored by Belgium.
"The coach told us to press high as soon as the game kicked off," Benteke told Belgian network RTBF.
"Their defender did not anticipate the back pass well and I got ahead of him and made for the goal."
Benteke hit his second goal two minutes before halftime after Axel Witsel had extended Belgium's advantage in the 19th and the Crystal Palace striker completed a hat-trick, his first for his country, by netting with a clever backheel in the 56th.
Dries Mertens and Eden Hazard also got on the scoresheet for Roberto Martinez's side, who top Group H with nine points and a superior goal difference to Greece.
Benteke has scored three times in five Premier League games for Palace since his 27 million pounds ($33.57 million) move from Liverpool in the close season and said he was feeling more confident again after a disappointing stay on Merseyside.
"I'm taking advantage of my current form to help the team. After a bad spell I'm now doing well again, and I want to continue like this," he added.
"Scoring a hat-trick is great. I would have preferred to have produced this display against a slightly tougher opponent, but I'm not going to start complaining."
($1 = 0.8042 pounds)
(Reporting by Richard Martin in Barcelona, Additonal reporting by Martyn Herman in London, Editing by Ken Ferris)
