MILAN, Feb 10 (Reuters) - Inter Milan battled to a 2-0 win at Catania on Sunday to remain eight points clear at the top of Serie A.
The hosts were the better side in the first half but Inter had a lucky break on 64 minutes when Esteban Cambiasso's tap-in from Javier Zanetti's header was allowed to stand despite him being just offside.
Substitute David Suazo netted with ease three minutes later to help the unbeaten champions up to 56 points and keep them clear of second-placed AS Roma, who put pressure on Inter by beating Reggina 2-0 on Saturday.
Cambiasso's strike is the latest in a number of controversial decisions which have gone Inter's way in recent weeks and following the goal Catania fans ironically applauded every decision of the referee.
Earlier substitute Alberto Paloschi finished superbly with his first touch in Serie A to hand a lethargic AC Milan a 1-0 win over Siena while Juventus won 2-1 at Udinese.
Paloschi, 18, found the far corner from the edge of the area on 63 minutes to help Milan in fifth go two points behind fourth-placed Fiorentina, who drew 2-2 at Atalanta on Saturday.
Milan have a game in hand against Livorno on Wednesday when they can jump into a Champions League spot having recently recovered from a woeful first half of the season.
'To score on your debut after 18 seconds on the field is incredible. I am very happy for him. He is a very determined and serious lad, the future is in his hands,' Milan coach Carlo Ancelotti told reporters of the youth team striker.
Ronaldo also started after recovering from another strain in an injury-ravaged season but he managed just 45 minutes in which he repeatedly looked dejected with his head down.
Milan, without injured Brazilian forwards Kaka and Pato, were hanging on at times with Mario Frick hitting the post and Tomas Locatelli having an effort ruled out for offside.
The pressure only eased when Siena captain Simone Vergassola was sent off for a handball which may have stopped a goalscoring opportunity on 82 minutes.
Third-placed Juventus also struggled until Mauro Camoranesi and Vincenzo Iaquinta netted in the second half after Andrea Dossena had given hosts Udinese an early lead.
Juve had won just once this year and looked likely to extend their bad run with sixth-placed Udinese bossing the first half.
Winger Camoranesi, fully fit after a thigh injury, headed in to spur on Claudio Ranieri's side before Iaquinta repeated Paloschi's trick by scoring straight after coming on.
The Turin side are 12 points adrift of Inter.