|Okaka played despite being on the verge of a move to Fulham [EPA]
Substitute Stefano Okaka scored with a stunning backheel two minutes from time to give flying Roma a 2-1 Serie A win over bottom side Siena.
Roma went level on points with second-placed AC Milan, who ended a difficult week by labouring to a 1-1 home draw with struggling Livorno.
Both sides moved eight points behind leaders Inter Milan, whose match at Parma was postponed because of snow, although Roma have played a game more.
The little-used Okaka was due to make a loan move to Fulham but was named in Sunday's squad because four Roma forwards were out injured, including Francesco Totti and Luca Toni.
The 20-year-old entered the fray on the hour after John Arne Riise's terrific volley put Roma ahead before Simone Vergassola equalised from a tight angle late in the first half.
Okaka made an immediate impact and then found the perfect moment to score his first league goal of the season with a powerful backheel from eight metres out.
"I told him 'you're not leaving now'. He fainted," Roma coach Claudio Ranieri joked to Sky TV, hinting Okaka would still go to Fulham when the window closes on Monday.
Milan could have done with a moment of magic themselves after another lacklustre performance at the San Siro following last Sunday's defeat by nine-man Inter and Wednesday's Italian Cup exit at the hands of Udinese.
Ronaldinho struck a post before the in-form David Beckham swung in a cross which keeper Francesco Benussi failed to hold, leaving Massimo Ambrosini to hook the ball home just before the break.
Livorno, whose coach Serse Cosmi resigned last week before changing his mind, deservedly equalised eight minutes into the second half when striker Cristiano Lucarelli prodded in Claudio Bellucci's scuffed shot.
A bad week for Fiorentina also ended on a dull note with a 2-2 draw at Cagliari which left the Florence club 11th.
Striker Adrian Mutu has been suspended for testing positive for a banned appetite suppressant and Fiorentina's bid to sign Antonio Cassano from Sampdoria as his replacement fell through.
Cassano was injured for Samp but they still won their second game in a row after a poor spell with Angelo Palombo and Giampaolo Pazzini setting up a 2-0 victory over lowly Atalanta.
Also in the bottom half, Catania drew 1-1 at home with Udinese and Bologna grabbed a 1-1 draw at Chievo.
Alberto Zaccheroni takes charge of free-falling Juventus for the first time at home to former club Lazio later.