Liverpool conceded top spot in Group A to Europa League opponents Anzhi Makhachkala after defeat in Moscow.
Giant striker Lacina Traore (pictured right) scored a brilliant individual goal as the visitors switched off seconds before half-time.
The result, the Reds' first-ever away defeat in the group stage and only their third loss in 22 European matches, allowed the Russian club to assume pole position.
Anzhi may play 1,000 miles away from their home in Dagestan because of security issues but they remain strong on Russian turf and made it five successive European home wins.
It was always going to be a tough assignment for Liverpool as manager Brendan Rodgers, with Sunday's trip to Chelsea in mind and unperturbed by a weakened team's Capital One Cup exit against Swansea last week, opted to leave his big-name stars at home.
As a result he selected nine Englishmen, in a starting XI with an average age of just under 24, in a 3-5-2 formation.
It meant Conor Coady, who captained England Under-17s to their first European Championship title in 2010, made his debut in an icy-cold Lokomotiv Stadium.
The Liverpool-born 19-year-old has progressed through the club's academy and was given his chance having been an unused first-team substitute three times.
Striker Adam Morgan, 18, was making only his second start but, having been prolific throughout youth level Rodgers remains hopeful he will eventually make the step up and he was given the difficult job of leading the line.
At the other end of the scale Joe Cole, on his 31st birthday, struggled to make an impact again after a woeful 45 minutes against the Swans.
The first half was a typically cagey European affair with chances at a premium.
All of which made it all the more remarkable that when presented with a shooting opportunity Jordan Henderson declined in the 23rd minute.
The 22-year-old spoke before the match about wanting to prove he has a future at Anfield but he will need to improve his decision making if that is to be the case.
Morgan showed good strength to hold off Odil Ahmedov and thread a pass through but from a 45-degree angle he opted to cut the ball back to the striker.
It probably showed a lack of confidence but chances in Europe do not come around that frequently and it was a waste.
Contrast that with former Barcelona forward Samuel Eto'o, Anzhi's £330,000-a-week marquee signing, who forced Brad Jones into a good save from Yuri Zhirkov's cross after the ex-Chelsea player had robbed Andre Wisdom near Liverpool's right touchline.
Henderson flicked on a tame near-post header from Downing's cross and Cole nodded Downing's inswinging free-kick wide before, in added time, Liverpool lapsed.
Traore brilliant spun Sebastian Coates with a left-footed touch and then lobbed Jones with his right for his fourth goal in six matches.
Cole at least made it out for the second half, which was more than he did last week, and set up Morgan to fire into the side-netting soon after the restart.
Eto'o replied with a curling shot which Jones claimed comfortably diving to his left while Traore and Rasim Tagirbekov flashed shots just past the post as the game began to open up.
Substitutes Suso and Dani Pacheco, on for Morgan and Coady, gave the forward line some more youthful impetus but it was the hosts who remained the more threatening with Jones making another good save from Traore's powerful header.
Cole's last contribution before being replaced by Oussama Assaidi was to force a close-range save from Vladimir Gabulov after he had fumbled Suso's shot.
But Traore should have finished off Liverpool when put clean through by Eto'o but he rolled his effort wide of the upright.
Henderson had a late chance to equalise but ballooned his shot well over.Liverpool 1 Anzhi Makhachkala 0
A superb strike from Stewart Downing saw Liverpool claim victory over Anzhi Makhachkala and move into top spot in Group A.
Downing cracked home an unstoppable effort from outside the box in the 53rd minute after coming in from the left flank.
The win was no less than the Reds deserved having been the better side for much of the contest, and they now lead the group with six points from three games.
Liverpool manager Brendan Rodgers fielded a strong side including the likes of Steven Gerrard and Luis Suarez, resisting the temptation to rest a host of players ahead of Sunday's Barclays Premier League derby at Everton and making only three changes from the win over Reading on Saturday.
It was clear Rodgers was not about to underestimate nouveaux riche Anzhi, who lead the Russian top-flight, and are overseen by one-time Chelsea boss Guus Hiddink and had former Barcelona and Inter Milan striker Samuel Eto'o (pictured right) up front.
The Reds were looking to bounce back from a 3-2 home defeat to Udinese in their previous Europa League outing and made a positive start without fashioning anything to really trouble visiting goalkeeper Vladimir Gabulov.
He easily collected a shot from Suarez in the 12th minute and then pushed away an effort by Glen Johnson before Jonjo Shelvey - scorer of three goals in the previous two group games - ballooned an attempt over the bar from the edge of the box.
Eto'o had been relatively quiet, miscontrolling on the occasion when the ball had come to him in a useful position in the area, and Liverpool continued to carve out half-chances, with Oussama Assaidi seeing Gabulov get behind his strike to the near post and then catching his free-kick.
Johnson found himself through on goal in the 35th minute, but failed to get a shot in and took a tumble under the attentions of Kamil Agalarov, with the referee waving the Reds defender's penalty claims away.
Nuri Sahin headed a corner over and Daniel Agger was next to make a foray forward from defence, trying his luck from distance with an effort that curled high and wide.
Anzhi registered an attempt on goal in first-half stoppage-time when Fedor Smolov fizzed the ball across Brad Jones and wide.
Rodgers added new impetus to his attack at the interval by introducing Raheem Sterling for Johnson, and there were encouraging signs for Liverpool soon after the break, with Martin Skrtel's powerful drive bringing a save out of Gabulov before Gerrard headed Shelvey's cross wide.
The Reds kept up the pressure and moments later they made the breakthrough as Downing, who had been shifted to left-back, cut in from out wide and smashed the ball into the net.
Suarez almost swiftly added another with a strike that went just the wrong side of the post, and Shelvey then sent a shot into Gabulov's arms.
With the lead still only at 1-0, though, Liverpool could not afford to switch off at the back and they survived a scare in the 70th minute when defensive sloppiness saw the ball come to Eto'o, whose effort was saved by Jones.
Assaidi and Suarez went down in the box in separate tussles with the referee only being moved to book the latter for protesting, before Mbark Boussoufa saw a shot deflect wide of Jones' goal.
Agger thought he had doubled Liverpool's advantage when he headed the ball from Gabulov's hand and lashed in, but he also only picked up a booking.
Anzhi issued further warnings, with Skrtel making a goal-line clearance to deny Mehdi Carcela and substitute Lacina Traore striking wide.
Gerrard then fired over and Carcela struck wide at the other end before the full-time whistle confirmed Liverpool's win.
Group A - 1 Liverpool 6 3 1 2 11 9 10 2 2 Anzhi Makhachkala 6 3 1 2 7 5 10 2 3 Young Boys Bern 6 3 1 2 14 13 10 1 4 Udinese 6 1 1 4 7 12 4 -5
Source: Newcastle United Mad