Andrea Marcato's last-minute drop goal handed Scotland their fourth defeat in this year's RBS 6 Nations – but Frank Hadden's men avoided a second successive wooden spoon by the skin of their teeth.
After conceding a penalty try during a poor start, Scotland scored two tries in 20 minutes through Ally Hogg and Mike Blair.
That was more than they had scored in the previous seven matches but they failed to build on it and Marcato struck the winning kick after a poor pass by Dan Parks had gifted the Italians a second try.
Italy maintained the attacking edge as they sought the five-point lead they needed and three came from Marcato's 35-yard penalty in the 71st minute.
Paterson completed a perfect Six Nations kicking record – to follow his 100% World Cup stats – by levelling from the 22-metre line two minutes later.
But Italy pinned Scotland back and Marcato won the game with a last-minute drop goal in a central position 22 metres out.
The Italians celebrated with Scotland's only consolation their superior points difference of three that saves them from finishing bottom again.
Scotland flanker Alasdair Strokosch admitted Frank Hadden's side were "gutted" after their dramatic last-minute defeat.
He told BBC 1: "We're absolutely gutted.
"We started the tournament badly but felt we progressed with every game up to the England match (Scotland won 15-9). We hoped to build on that here."
"It was a solid performance in the first half but we took our foot off the gas I think," said Strokosch, whose side led 17-10 at the interval.
"We dropped our intensity. We'd had lots of bodies coming onto the ball and flying in but in the second half we didn't have too many options."
The full article contains 305 words and appears in The Scotsman newspaper.