( CNN ) -- AC Milan are all but through to the quarterfinals of the Champions League after thrashing Arsenal 4-0 at the San Siro on Wednesday . Brazilian striker Robinho scored twice as the Serie A champions dominated the first leg of the last-16 tie with the north London club . Kevin Prince Boateng put Milan ahead in the 15th minute with a sumptuous half-volley after chesting down a chipped pass from Alberto Nocerino . The Ghana midfielder 's strike flew in off the underside of the bar leaving Wojciech Szczesny with no chance . Robinho doubled the lead seven minutes before the break heading home a cut-back from Zlatan Ibrahimovic . Despite the arrival of Thierry Henry in the second half ( his last appearance for the Gunners before he returns to the New York Red Bulls ) things quickly went from bad to worse . In the 49th minute , Ibrahimovic and Robinho combined again on the edge of Arsenal 's penalty area before a slip by Thomas Vermaelen gifted the Brazilian a free shot which he put past Szczesny with ease . Robine Van Persie forced a fine save from Christian Abbiati in the 65th minute but it was a rare chance for the Dutch striker on a miserable night for Arsene Wenger 's team . Ibrahimovic completed the rout converting from the penalty spot after he was brought down by Johan Djourou 12 minutes from the end . `` We were never in the game , we were very poor both offensively and defensively , '' Wenger said , AFP reported . `` It was shocking to see how we were beaten everywhere , it was the worst performance in Europe by far . There was not one moment during the 90 when we were really in the game , '' he added , AFP reported . The return leg at the Emirates Stadium will be played on March 6 . Opinion : Suarez saga harming Liverpool 's global brand . In the other Champions League match played Wednesday , Russian champions Zenit St Petersburg came from behind to beat Portugal 's Benfica 3-2 in the first leg of their last-16 tie . Roman Shirokov scored twice while substitute Sergei Semak got the other . Benfica 's goals came from defender Maxi Pereira and Paraguayan striker Oscar Cardozo , both after errors by goalkeeper Yury Zhevnov . Benfica took the lead in the 20th minute courtesy of a goal from Maxi Pereira before Zenit leveled the scores seven minutes later when Shirokov struck a sweet volley to score his first of the night . Semak put Zenit in front in the 71st minute before Oscar Cardozo equalized three minutes from the end . But Zenit responded immediately as Shirokov pounced on a defensive mistake to tap home the winner with two minutes remaining . `` My players showed really good skill . They showed a lot of heart to win the match in such a grave situation . However they did exactly what we decided to do ahead of the match . We won deservedly tonight , '' Zenit manager Luciano Spalletti said , AFP reported . Meanwhile in Serie A , Juventus missed out on the chance to go top after being held to a 0-0 draw at Parma . Juve 's 10th draw of the league season ( and their sixth on the road ) means that AC Milan still head the league table but only by one point . The Rossoneri have also played one extra game . The result lifts Parma to 12th place with 28 points . In Serie A 's other match Wednesday Guido Marilungo scored the winner for Atalanta in a 1-0 win over Genoa . The strike 12 minutes from the end lifts Atalanta to 13th with 27 points . Genoa remain in 10th with 30 points .
AC Milan demolish Arsenal 4 - 0 at the San Siro to almost guarantee place in last 16 . Zenit St Petersburg beat Benfica 3 - 2 in first leg of last 16 encounter . Juventus drop back on the road in Serie A to finish in second behind AC Milan .