Goals either side of half-time from Diogo Jota and Mohamed Salah initially put Klopp's men on track for another win after Ethan Pinnock opened the scoring. Alas, the six-time European champions couldn't shake off the newly promoted side, with Vitaly Janelt and Yoane Wissa scoring to cancel out Curtis Jones' wonder strike.
It was a "back to basics" switch that allowed the visitors to fight back against Brentford, as they mixed things up between hopeful crosses into the box, breaking the offside trap and encouraging attempts from long range. They realised that keeping it on the deck wasn't going to work quite as well as it usually does and that quick passing movement would eventually draw the Bees out of their shell as they became more fatigued.
Sloppy defensive errors were aplenty for Liverpool, and all night long, they just couldn't seem to get themselves right at the back. There was also a pretty clear gulf between the two sides with respect to their physicality as Brentford bullied them off the ball time and time again. They couldn't deal with the direct nature of their opponent's attacks and, ultimately, the visitors were too weak to warrant winning the game.
Manager rating out of 10
Jurgen Klopp, 6 -- There are few better managers at handling tight games than Klopp, but that wasn't entirely the case on Saturday evening. The Reds' counterattack wasn't working in the first half and he made suitable alterations to change the status quo, but the German wasn't urgent enough with his substitutions, ultimately making just one midway through the second half.
Player ratings (1-10; 10 = best, players introduced after 70 minutes get no rating)
GK Alisson, 5 -- Made a handful of good saves but ultimately conceded three goals, with the third seeing him come off his line a bit too quickly.
DF Trent Alexander-Arnold, 4 -- Guilty of some poor positional play, a tackle that could've led to a penalty and being overmatched for two of Brentford's goals. It all amounted to a bad night for the 22-year-old.
DF Joel Matip, 5 -- Produced a brilliant goal-line clearance in the first half that probably won't be remembered thanks to some lapses in concentration that contributed heavily to the final scoreline.
DF Virgil van Dijk, 6 -- The Dutchman needs to stand his ground more in aerial duels. but in an overall sense, he got Liverpool out of jail on multiple occasions, including in a vital late one-on-one with Ivan Toney.
DF Andy Robertson, 5 -- The Scot offered up far too much space for Brentford and wasn't sharp enough both in and out of possession.
MF Jordan Henderson, 6 -- The game got away from the captain ever so slightly in the second half, but he was still a stable presence in the middle of the park with a nice cross and assist to his name too.
MF Fabinho, 6 -- Pulled off a stunning assist for Salah's goal, but it wasn't enough to make up for the gaps he left in midfield and the lethargic nature of his overall play.
MF Curtis Jones, 7 -- The youngster was easily Liverpool's most exciting player on the night, and his impact shone through in the form of a 67th-minute thunderbolt.
FW Mohamed Salah, 7 -- Salah was outsmarted at every turn by Brentford's defenders right up until he broke free of his marker and tapped the ball in to make it 2-1.
FW Diogo Jota, 7 -- A delightful 31st-minute header largely defined a solid enough performance for Jota, who proved to be Liverpool's best forward of the day.
FW Sadio Mane, 5 -- Didn't fight hard enough for the ball whenever a 50-50 was there to be won and never really looked like he was scoring when he found an opening.
FW Roberto Firmino, 6 -- Got into a string of good positions upon being introduced but didn't quite have the end product required to make a substantial impact.