Tevez scored from close range with three minutes remaining at the Stade de Gerland to extend two-time champion United's unbeaten record in Europe's top club competition this season to seven games. Karim Benzema put Lyon ahead after 54 minutes.
It's always crucial to get an away goal,'' United striker Wayne Rooney told an English channel. I felt we controlled the game for most of it. They had a few chances and stuck the ball in.''
In today's other first-leg matches, defending champion AC Milan drew 0-0 at Premier League leader Arsenal and Fenerbahce defeated visiting Sevilla 3-2. The return games are scheduled March 4. Liverpool, Roma and Schalke all won yesterday, while Chelsea drew 0-0 with Olympiakos.
United lacked fluency in the first half against Lyon and center-back Rio Ferdinand had to make several interventions to stop attacks by the home team.
Ferdinand almost put the ball into his own net after 24 minutes when he sliced an attempted clearance from a Jeremy Toulalan cross. Rooney came close at the other end moments later, though goalkeeper Gregory Coupet blocked his effort.
Benzema shot over in the 26th minute and United had chances near the end of the first half as Cristiano Ronaldo tested Coupet with a free kick, and then headed over the bar.
The 20-year-old Benzema, who has been linked with a move to United in U.K. newspapers, opened the scoring nine minutes after half time. Receiving the ball with his back to goal 20 yards out, he spun and struck a low shot into the corner of the net.
Lyon, aiming to reach the quarterfinals for the fourth time in five seasons, held on until the 87th minute. Nani's cross hit a defender and dropped to Tevez, who slammed the ball into the net from five yards out for his 15th goal of the season.
Celtic, which in 1967 became the first British team to win the European Cup, twice squandered the lead against Barcelona to end its run of three straight home wins in Europe.
Jan Vennegoor of Hesselink scored from a diving header after 16 minutes for his first goal in 16 European matches. The lead lasted only two minutes before Lionel Messi got the first of his two goals, looping the ball over Artur Boruc after exchanging passes with Andres Iniesta.
Barry Robson headed Celtic back in front in the 38th minute and Thierry Henry's curling shot tied the match seven minutes after half time. Messi got the winner with 11 minutes left when he tricked the Celtic defense and beat Boruc with a low shot.