The Japan midfielder curled a spectacular free-kick nine minutes from time to secure a precious win for Celtic over the Premiership leaders, who were on course of a satisfying away draw.

Celtic are joint leaders with United in Group F with nine points, two ahead of third-placed Benfica, who beat FC Copenhagen 3-1.

The Scottish giants ensured their progress even if they lost the last match in the group stage against Copenhagen because they overruled United in the head-to-head record.

Nakamura broke the deadlock in a nervy game at Celtic Park in the 81st minute when he curled a venomous free-kick from 30 meters into the left top corner of Edwin van der Sar's net.

The visitors almost grabbed the point they need to advance deep into the injury time when they were awarded a debatable spot-kick after Shaun Maloney handled Cristiano Ronaldo's free-kick inside the area.

French international striker Louis Saha stepped up to deliver the penalty but Boruc dived brilliantly to his right to block the powerful shot.

Elsewhere, Fabrizio Miccoli notched a brace to help Portugal's Benfica cruise past Copenhagen 3-1.

The Italian striker scored twice in the 16th and 37th minutes after Benfica's left-back Leo broke the deadlock in the 14th minute.

Marcus Allback scored the consolation for the Danish side just before the end.