LONDON — Villarreal held defending champion Manchester United to a 0-0 Champions League draw and a referee sent off the wrong player in Aalborg's goalless tie at Celtic.

On another night of surprises and comebacks, Arsenal snatched a late equalizer in a 1-1 draw at Dynamo Kiev and Lyon hit back from two goals down with 17 minutes to go to draw 2-2 with Fiorentina.

Daniel van Buyten captured a 1-0 victory for visiting Bayern Munich at Steaua Bucharest in a meeting of two former European champions and nine time winner Real Madrid beat BATE Borisov 2-0.

Veteran striker Alessandro Del Piero netted the only goal as Juventus returned to European football's premier competition with a 1-0 victory over UEFA Cup champion Zenit St. Petersburg.

FC Porto, winner under Jose Mourinho four years ago, captured a 3-1 victory over Fenerbahce, guided by Luis Aragones, the man who led Spain to its Euro 2008 triumph.

After Romanian champion CFR Cluj upset AS Roma 2-1 on Tuesday, more surprises followed in Wednesday's matches.

Villarreal hit the post at Old Trafford and followed up its two draws with Manchester United from 2006 with another. In a bad omen for Alex Ferguson's team, his side was eliminated in last place in its group three years ago after tying twice 0-0 with the Spanish club.

Not even the return of Cristiano Ronaldo made a difference. The Portuguese star, who said he wanted to move to Real Madrid but decided to stay at the club, returned after being sidelined with an ankle injury and went on as a second half substitute.

While Ronaldo was given a warm welcome by the Red Devils fans, there were some embarrassed faces at Celtic Park in the other Group E game.

Barry Robson fired a 30th minute penalty straight at goalkeeper Karim Zaza after Aalborg defender Steve Olfers brought down Shaun Maloney.

Ten minutes from the end, Aalborg's Michael Jakobsen hauled down Celtic striker Giorgios Samaras and was amazed to see Italian referee Matteo Trefoloni show the red card to teammate Michael Beauchamp.

The results leave all four teams level on one point with no goals scored.

Bayern Munich, a four-time winner aiming to capture the title for the first time since 2001, tops Group F after its triumph in Bucharest.

Fiorentina will be furious it couldn't hold on to a two-goal lead at Lyon after Alberto Gilardino scored first half strikes in the 11th and 42nd minutes.

Frederic Piquionne replied in the 73rd and Karim Benzema equalized with five minutes to go.

Likewise Ismael Bangoura's 64th-minute penalty appeared to be guiding Dynamo Kiev to victory at home to 2006 runner up Arsenal, which seemed to be headed for another miserable result on its travels to eastern Europe. But Gunners defender William Gallas leveled in the 88th for a Group G point.

Porto went top of the standings with Lisandro Lopez (11th) and Lucho Gonzalez (14th) putting the Portuguese team in charge at home. Spanish striker Daniel Guiza replied for Fenerbahce in the 30th but Lino added a third in the final minute.

Juventus was back in the Champions League group phase for the first time since it was relegated from Serie A over a match-fixing scandal that shamed Italian football.

Veteran Del Piero scored the only goal of the game in the 76th minute and Juve is neck and neck with another European powerhouse, Real Madrid, which brushed aside Belarussian side BATE with goals by Sergio Ramos (11th minute) and Ruud van Nistelrooy (57th).