Lopez, who moved to Milan on loan from Catania last month, scored
the equalizer in the 77th minute after Antonio Di Natale gave Udinese a
19th-minute lead.
Lopez then set up Stephan El Shaarawy, who struck for the
second time in a week, five minutes from time, to snatch the victory for Milan.
Elsewhere, Mauricio Pinilla scored against his parent club
to see Cagliari beat Palermo 2-1.
With Juventus' game at Bologna postponed, Milan will end the
weekend two points clear of the Turin side, which has two games in hand.
Udinese had not lost a home game all season, winning 10 of
its 11 matches at Stadio Friuli and knew that another victory would see it draw
level with second-placed Milan.
The home team was certainly the better side in the first
period and richly deserved its halftime lead. Di Natale latched onto Gelson
Fernandes' long ball and his shot was deflected past Marco Amelia by Milan
defender Thiago Silva.
It was almost immediately worse for Milan as Amelia was
forced into a smart save to deny Mauricio Isla. Di Natale also had a good
chance to double his tally but fired wide.
Milan was clearly missing star striker Zlatan Ibrahimovic,
who was serving the first of a three-match ban. The only chance it created in
the first half was an El Shaarawy strike in stoppage time.
It was more of the same after the interval and as Milan
searched for the equalizer it left itself more exposed at the back and Amelia
was forced into two stunning saves to deny Maurizio Domizzi and Danilo.
Lopez, who came off the bench in the 66th, leveled for
Milan. Udinese goalkeeper Samir Handanovic parried El Shaarawy's shot but only
as far as Lopez, who fired it home.
The Argentine striker repaid the favor five minutes from
time as he served El Shaarawy, who volleyed home the winner.
In Sardinia, Pinilla, who moved on loan to Cagliari last
month, came back to haunt Palermo.
Cagliari took the lead in the 56th minute when Victor Ibarbo
crossed into the area for a sliding Pinilla to open the scoring. It was
Pinilla's second goal in four games for Cagliari.
The home side doubled its advantage in the 81st when
Pinilla's free kick was punched clear by Palermo goalkeeper Emiliano Viviano
but fell straight to Daniele Dessena who rifled the ball into the back of the
net.
Palermo grabbed one back moments later when Cagliari
defender Gabriele Perico handled in the area. Abel Hernandez stepped up to
convert the penalty.
