Bayern Munich's Xabi Alonso was sent off in his 100th Champions League game as his side played out a drab stalemate against Shakhtar Donetsk in Ukraine.
The former Liverpool midfielder picked up a second yellow card with 25 minutes remaining and neither side threatened after his dismissal.
Bayern - Champions League winners in 2013 - went close twice through Thomas Muller in the first half but he pulled a shot wide and fired over from 18 yards.
Despite boasting the top scorer in the competition in Luiz Adriano, Shakhtar were unable to work Manuel Neuer with any effort of quality.
But Mircea Lucescu's side were organised throughout, a feat made more impressive given they have not played a competitive game since December due to their league's winter break.
The Ukraine champions are also still contending with playing all of their matches in the western city of Lviv, several hundred miles from their home ground which is too close to a conflict zone in the war-torn country.
They defended with energy whenever Bayern caught a glimpse of space, but had just one attempt at goal in the entire 90 minutes.
Bayern - fresh from an 8-0 win over Hamburg on Saturday - were unable to pose meaningful threat, but they have not lost at home since defeat in the semi-final of this competition last year and will start as heavy favourites in the second leg on 11 March.