Karen Carney's cool injury-time chip gave England a dramatic win in their opening Euro 2005 match.
An own goal from Sanna Valkonen was followed by Amanda Barr's header to put the hosts 2-0 up at the interval.
But Finland, who had already hit the bar, pulled one back through Anna-Kaisa Rantanen and drew level in the last minute as Laura Kalmari tapped in.
Yet there was time for the 17-year-old Carney to delight a crowd of 29,029 at the City of Manchester Stadium.
England, playing the only team in the competition ranked below them, were desperate to impress but struggled to impose themselves early on in front of a record attendance for a Women's European Championship match.
The Finns looked slick in possession but were unable to find a breakthrough and fell behind to a scrappy goal.
Eighteen minutes were on the clock when goalkeeper Satu Kunnas made a mess of Carney's low free-kick. Defender Valkonen got the last touch before the ball crossed the line but there was little she could do about it.
Finland could have levelled on 25 minutes when Anne Makinen's looping header beat keeper Jo Fletcher but came back off the bar.
England doubled their lead when Kelly Smith's fierce drive hit the woodwork and bounced kindly for Barr to head over Kunnas towards the goal.
The Finnish keeper's frantic efforts to clear were in vain as Hungarian referee Gyongyi Gaal ruled the ball had crossed the line after consulting her assistant.
But Rantanen shook England's nerves as she side-footed home from the edge of the box.
And when Kalmari tapped in on 89 minutes it looked as though the Finns had salvaged a point - only for Carney to have the final say.
England head coach Hope Powell:
"We showed resilience and got the winner in the last minute of play.
"I'm overjoyed with that, perhaps not overjoyed with the performance.
"We'll perhaps put that down to nerves because we were very cagey. It proves we've got more to come. And I would like to thank the crowd - fantastic."
Finland coach Michael Kald:
"What can I say? We did a great second half and we did some good work. We just have to learn from it.
"I'm very proud of the team and I think people back home in Finland are very proud of the Finnish team."