Aston Villa started the week atop the 36-team table but their winning run ended after a bizarre penalty was awarded when defender Tyrone Mings picked up the ball in the area at Club Brugge, resulting in a 1-0 loss that sent the English club plummeting to eighth place.
Paris Saint-Germain, in their first season without Kylian Mbappe, trail far behind in 25th after Atletico Madrid scored in stoppage time to seal a 2-1 win for the Spanish team at Parc des Princes.
Barcelona's blistering scoring form continued in a 5-2 win at Red Star Belgrade - a seventh straight win since the start of October at a rate of four goals per game. Robert Lewandowski scored twice and has 21 this season.
Robert Lewandowski was the two-goal hero for Barcelona. (AP PHOTO)
Inter Milan stifled Arsenal in a 1-0 win at San Siro sealed by Hakan Calhanoglu's penalty in first-half stoppage time.
Inter are unbeaten on 10 points and in fifth place, one below Brest who won 2-1 at Sparta Prague. The French debutants looks sure to advance to the knockout phase starting in February.
Atalanta won 2-0 at Stuttgart to stay unbeaten on eight points and Salzburg got their first goals and points in a 3-1 win at Feyenoord.
Bayern Munich won 1-0 at home to Benfica in a game that was delayed 15 minutes by crowd congestion and then was played in a muted atmosphere because of a medical incident for a fan.
Shakhtar Donetsk playmaker Heorhiy Sudakov had a fine assist and an even better goal in a 2-1 win for the Ukrainian champion against Young Boys. Shakhtar's No. 10 showed why he is expected to be the club's next big-money sale.
Liverpool, which on Tuesday routed Bayer Leverkusen 4-0, leads the new single-standings format at the midway point of the eight-round program.
Liverpool are the only team with four straight wins, while five teams have four losses. They are Leipzig, Sturm Graz, Young Boys, Red Star Belgrade and Slovan Bratislava.
Two Italian teams - Inter Milan and Atalanta - have yet to concede a goal in four games.
Brugge's Hans Vanaken (left) celebrates scoring the winner against Aston Villa. (AP PHOTO)
Villa had led the 36-team Champions League standings after three straight wins without conceding a goal — and it took a bizarre incident before goalkeeper Emiliano Martinez was eventually beaten.
Mings was punished for picking up the ball when Martinez seemed to restart play with a goal kick passed forward to his teammate. Mings walked a couple steps to gather the ball with his left hand and returned to place it in the six-yard box.
Brugge captain Hans Vanaken placed the 52nd-minute spot kick to Martinez's left as the World Cup-winning Argentina goalkeeper dived to his right.
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