Gerard Houllier paid tribute to Darren Bent after the debutant inspired Aston Villa to a 1-0 victory over Manchester City.
The striker, signed from Sunderland this week in a controversial big-money move, netted the only goal of the game to ease Villa's relegation worries.
He slotted the ball home from close range after Joe Hart could only parry a curling effort from Ashley Young on 18 minutes.
Houllier said: "The finish was that of a natural-born finisher, something you cannot teach somebody. That is what he is here for, to score goals.
"Roberto Mancini told me before the game that I'd signed a great player and that is a tremendous start for him."
Expectations will remain high for Bent over the course of his Villa career due to the hefty £18million price tag on his head but Houllier has been impressed by his coolness under pressure.
The French tactician maintains that he had no doubts about Bent's state of mind following a week which has seen claim and counter-claim from Sunderland and Villa regarding his transfer.
Houllier continued: "I thought the boy handled the pressure very well.
"He had settled in well during the week, knows a lot of players from the international scene, and I felt he was ready to play."
Aside from Bent's heroics, Villa also had to defend for long periods as City dominated possession.
And Houllier was proud of the fighting spirit demonstrated by his side as they made amends for a 4-0 drubbing at Eastlands last month.
He said: "That defeat really affected us and we were at rock bottom then.
"But since the start of the new year things have got better and this game epitomised what we want to do.
"We showed tremendous resolve against a very good side and also rode our luck at times."