Nikola Vlasic's early strike proved enough for CSKA Moscow to cling on for a famous win over Real Madrid in the Champions League.
Vlasic pounced on a rare error by Toni Kroos to fire the opener and the Russians defended resolutely and even survived the bizarre injury-time sending-off of goalkeeper Igor Akinfeev.
Mariano, Karim Benzema and Casemiro all hit the woodwork for Real while Luka Modric and Raphael Varane were among those who missed easy chances to drag their side back into the game.
Julen Lopetegui started with Modric on the bench on a night which saw Gareth Bale and Sergio Ramos miss out due to injury.
Any hopes Real had of coasting to a second-consecutive win in the group were dashed almost immediately when Kroos' loose ball was intercepted by Vlasic, who slid the opener past Keylor Navas.
Kroos sought to atone for his mistake by firing straight at Akinfeev, then Dani Ceballos headed just wide from a Marco Asensio cross as the visitors showed signs of life.
But their uncharacteristic defensive frailty emerged again just before the quarter-hour mark when Fedor Chalov had a shot blocked in the box and Viktor Chernov headed a fine chance wide from the resulting corner.
Casemiro came close to connecting with Varane's header across the face of goal as the visitors began to press, and the Brazilian came close on the half-hour mark when he rattled a shot against the inside of the post with Akinfeev beaten.
Akinfeev saved well from Dani Carvajal then, five minutes before the break, Real hit the woodwork for a second time when Benzema powered a header against the bar from Asensio's cross.
Carvajal exited through injury before the break, and Lopetegui opted to send Modric on after an hour following another near-miss in which Chalov headed just over the bar.
Kroos came close from long range before a frantic final 10 minutes in which Mariano shot over the bar then Akinfeev superbly tipped away an effort from Ceballos.
Modric and Varane headed close-range efforts wide of target and Mariano clattered the woodwork again.
Yet there was still time for one final dramatic twist as Akinfeev was needlessly sent off for apparent dissent deep into added time, enabling teenage keeper Georgi Krynats to play a tiny part in a famous night for CSKA.