Inter Milan opened the defense of its Champions League title with a 2-2 draw at tournament newcomer FC Twente on Tuesday while Barcelona signaled its intent with a 5-1 home thrashing of Panathinaikos.
Inter went ahead in the Netherlands through Wesley Sneijder but needed a 41st-minute goal by striker Samuel Eto'o to earn a point from the Group A opener.
Lionel Messi scored twice and missed a penalty as Barcelona, which lost to Inter in the semifinals last season, started group play with a convincing victory at the Camp Nou. David Villa, Pedro Rodriguez and Daniel Alves also scored for the Spanish champions.
In Group C, Manchester United was held to a goalless draw at home to Rangers in a match marred by a serious ankle injury to United winger Antonio Valencia, and Valencia thrashed newcomer Bursaspor 4-0 away.
Sneijder, who starred for the Netherlands at the World Cup, tapped in a rebound to open the scoring after Twente goalkeeper Nikolay Mihaylov failed to hold on to Diego Milito's shot.
Theo Janssen equalized for Twente with a curling free kick in the 20th before Milito's own goal put the Dutch side ahead 10 minutes later.
Eto'o, who scored the winner against Udinese at the weekend, found the target again with a low 25-yard drive to rescue Inter, which is struggling for form in the early part of the campaign after winning an unprecedented treble - Champions League, Serie A and Italian Cup - last season.
"A draw against Inter is a good result for us," said Twente coach Michel Preud'homme. "We could have won the match."
In the other match in the pool, Werder Bremen recovered from going two goals down to draw 2-2 with Tottenham, which was making its debut in the tournament.
A Petri Pasanen own goal and a header by Peter Crouch gave Spurs a great start but goals by Hugo Almeida and Marko Marin brought Werder level.
Barcelona bounced back from a humiliating 2-0 home defeat to Hercules in the Spanish league by routing Panathinaikos, which took the lead through Sidney Govou in the 20th minute.
Argentina forward Messi took his tally for the season to six goals in five games by first equalizing with a well-taken finish and then adding a third after offseason signing Villa had made it 2-1.
Panathinaikos goalkeeper Alexandros Tzorvas denied Messi a hat trick with a penalty save in the 54th minute but Pedro and Alves piled on the agony for the visitors from Greece.
"Things worked out well and it's always nice to start the Champions League with a victory," Pedro said. "We knew we had to win."
Dame N'Doye's late winner handed FC Copenhagen a 1-0 victory against Rubin Kazan in the other Group D match.
United manager Alex Ferguson feared being without Valencia for the rest of the season after saying the Ecuador winger sustained what could be "a dislocation and a fracture" in an innocuous second-half challenge in the draw with Rangers.
"He seemed to dig his toe in the turf. Unfortunately, it's a bad one," Ferguson said.
An almost second-string United, featuring recalled England striker Wayne Rooney and nine other players who did not start against Everton in the Premier League on Saturday, failed to break down a stubborn Rangers defense at Old Trafford.
United midfielder Darron Gibson came closest to breaking the deadlock with a raft of long-range efforts.
Bursaspor, one of two other teams playing in the Champions League for the first time, was handed a tough introduction to life in Europe's elite club competition.
Tino Costa opened the scoring for Valencia in the 16th minute with a 35-yard shot and striker Aduriz dived to head in the second. Pablo Hernandez and Roberto Soldado added more goals in the second half for the Spanish team.
In Group B, Brazil international Michel Bastos scored an opportunist 21st-minute lob as last season's semifinalist Lyon won 1-0 against 10-man Schalke.
Schalke center half Benedikt Hoewedes was sent off 13 minutes later for a high tackle on Lyon forward Jimmy Briand.
In the other group match, goals from Luisao and Oscar Cardozo gave Benfica a 2-0 win over debutant Hapoel Tel Aviv.
