Real Madrid turned in an unconvincing performance as they scraped past Czech outfit Viktoria Plzen with a 2-1 win at the Santiago Bernabeu on Tuesday evening.
Karim Benzema opened the scoring after just 11 minutes when he headed home Lucas Vazquez's dinked cross to settle the hosts' nerves, but David Limbersky and Patrik Hrosovsky spurned chances to equalise before the half-time whistle.
Within 10 minutes of the restart, Marcelo had clipped an effort over Plzen 'keeper Ales Hruska to double the home advantage, but Hrosovsky set up a tense finale when he pulled a goal back with 11 minutes to play.
The result sees Los Blancos retain Group G top spot, but the performance failed to ease any pressure on manager Julen Lopetegui, ahead of Sunday afternoon's El Clasico meeting with Barcelona.
From the off there was an evident desire from the hosts to react and put their recent adversity to bed, and within five minutes they almost had their wish as Sergio Ramos directed a Toni Kroos corner onto the post.
Real suffered an early scare, though. Roman Hubnik's speculative pass drifted beyond makeshift right-back Vazquez and Milan Petrzela forced Keylor Navas into a low save, before driving the rebound into the side netting.
Within a matter of seconds, Vazquez floated a cross to the far post and Benzema was on hand to place a header past Hruska, a goal that moved him fourth on the list of all-time Champions League goalscorers.
The goal seemed to set the tone, yet the Plzen threat would not abate. Limbersky dinked wide from close range and Hrosovsky passed up a golden chance when his poor connection on a cross from the right prevented him from volleying past Navas.
Lopetegui - who is reportedly on the verge of losing his job after 13 games - replaced Isco with debutant Federico Valverde after the break and the 20-year-old introduced himself by feeding Gareth Bale, who set up Marcelo to dink the second from close range.
The goal, arguably, should have taken the wind of out Plzen's sails, but moments after Vazquez headed Marco Asensio's cross wide, Hrosovsky calmly tucked his effort beyond Navas into the bottom right corner.
But for some robust defending from Nacho, Michal Krmencik could have equalised for the visitors and although uncertainty remains, Real held on to claim all three points.
Man of the match - David Limbersky
The veteran left-back turned in an impressive performance at the Bernabeu on Tuesday, clearly not overawed by Plzen's opposition. His overlapping runs put makeshift Real right-back Vasquez to the test on numerous occasions and the 35-year-old almost capped his performance in the Spanish capital with a goal, though he clipped his effort across the face of Navas' goal in the first half.
Opta facts
Real Madrid are unbeaten in their last 27 group stage games at the Santiago Bernabeu in the Champions League (W24 D3), in a run dating back to November 2009.
Viktoria Plzen have lost seven of their eight away games in the Champions League (W1), shipping at least two goals in each defeat.
Real Madrid have beaten more different opponents than any other team in Champions League history, with Viktoria Plzen being the 57th side they have won against in the competition.
Real Madrid striker Benzema is now the outright fourth top scorer in Champions League history (57), overtaking Ruud Van Nistelrooy (56) with this evening's opener.
Benzema became the third player to score in 14 consecutive Champions League campaigns, following Raúl and Lionel Messi.