Toni Kroos' mistake proved costly as Real Madrid's goalscoring problems continued on Tuesday with a surprise 1-0 defeat to CSKA Moscow in the Champions League.
Gareth Bale and Sergio Ramos were among a number of key players missing at the Luzhniki Stadium but it was Kroos' dreadful backpass that allowed Nikola Vlasic, on loan from Everton, to put CSKA ahead after just 68 seconds.
Madrid searched for an equaliser but, despite hitting the woodwork three times, were resisted by a determined CSKA defence. The reigning European champions have now failed to score in three consecutive matches.
CSKA's veteran goalkeeper Igor Akinfeev was sent off deep into added time after picking up two yellow cards for dissent but nothing could spoil the hosts' victory.
They climb above Madrid in Group G, with Julen Lopetegui's side lacking spark, thrust and cutting edge in attack. They missed Bale, Isco and, perhaps even, the lethal touch of Cristiano Ronaldo.
Bale and Ramos were both left at home to rest by Lopetegui while Isco and Marcelo are recovering from an appendix operation and calf injury respectively. Luka Modric started on the bench.
The absence of the established names meant a youthful line-up which included a debut for left-back Sergio Reguilon, the 21-year-old who has been with the club's academy since the age of eight.
Dani Ceballos and Marco Asensio both started too while summer signing Alvaro Odriozola came on in the second half for his Champions League debut. All three are 22.
Lucas Vazquez, reduced to a fringe player so far under Lopetegui, was given a rare outing while Keylor Navas came in for Thibaut Courtois in goal to continue the policy of one in La Liga and the other in Europe.
Madrid were three down by half-time against Sevilla last week and this time they were behind within two minutes.
It was entirely self-inflicted as Kroos tried to half-volley a bouncing ball back to Navas but Vlasic read it and intercepted. Raphael Varane was slow to react and the weaving forward finished into the corner.
Madrid hardly troubled CSKA during the first half even if Casemiro's long-range shot clipped the outside of the post and Karim Benzema's header plopped off the top of the crossbar.
Mariano Diaz and Modric finally came on for Casemiro and Vazquez shortly before the hour but even FIFA's best player in the world was unable to engineer any penetration through midfield.
The hapless Karim Benzema dragged a shot on the turn and Ceballos had a deflected effort pushed wide by Akinfeev, who was shown a red card for dissent in the dying moments.
Mariano headed Ceballos' cross onto the post for one final chance but Madrid could hardly complain.
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