Liverpool win 3-2 on aggregate
Liverpool lost in Europe for the first time in 14 matches but still beat CSKA Sofia 3-2 on aggregate to reach the group stage of the Champions League.
With Rafa Benitez's 3-1 up from the first leg, they were expected to easily sweep aside the Bulgarians at Anfield.
But Valentin Iliev's sweetly-struck shot put Sofia ahead early on and Yordon Todoro almost reduced the deficit still further shortly after.
John Arne Riise went closest for the Reds, who made hard work of the tie.
Liverpool were probably not helped by the lack of continuity in the team.
Steven Gerrard was out injured, while Jose Reina, Xabi Alonso, Jamie Carragher and Bolo Zenden were all rested.
In came Scott Carson, Josemi, Dietmar Hamann, Riise and Darren Potter.
Following the departure of Milan Baros to Aston Villa on Tuesday, Djibril Cisse and Fernando Morientes were partnered up front.
It gave the pair the chance to show Liverpool would not need to make the much-rumoured return of Michael Owen a reality.
And they did well, initially, with Cisse unlucky not to lift his shot over Sofia keeper Dejan Maksic when through on goal and, later, Morientes firing off target after linking up well with his strike partner.
But after looking confident for the opening 10 minutes, the European champions then started to look anything but.
Sofia began to stroke the ball around crisply and their one-touch passing left Mohammed Sissoko, in particular, bamboozled.
Far too often the long-legged midfielder was too quick to go to ground, finding himself bypassed.
And it was a Sissoko lunge which led to Sofia's breakthrough, when he conceded a free-kick on the right-hand edge of the penalty area.
With the set-piece taken quickly, and short, Liverpool stood and watched as centre-back Iliev struck a superb, curling shot into the left corner.
Shortly after, the visitors' fluid passing nearly created a second goal but the influential Yordon Todorov shot over after Carson's clearance had fallen to him.
Liverpool emerged more determined after the break and Riise - by some way his side's best player - went close three times.
The Norwegian had a fizzing drive tipped over and then smashed a shot narrowly wide after a neat lay-off from Morientes.
And on the 65 minutes, it was Riise's deflected shot which whistled wide.
As Sofia pushed forward, Morientes had a chance to end the tie as a contest but couldn't supply the finish his dribble had deserved.
The poor finishing did little to ease the nerves in Anfield and they were frayed even more when Gargorov lashed a 20-yard free-kick inches wide of a post.
Sissoko hit the bar late on, but it was not a convincing performance by Liverpool, although they never looked like completely surrendering their first-leg lead.
Liverpool: Carson, Finnan, Josemi, Hyypia, Warnock (Zenden 64), Potter (Luis Garcia 45), Hamann, Sissoko, Riise, Cisse (Sinama Pongolle 83), Morientes.
Subs Not Used: Reina, Alonso, Carragher, Barragan.
CSKA Sofia: Maksic, Zabavnik, Iliev, Gueye, Silva, Todorov, Gargorov, Hidiouad, Yurukov (Sakaliev 72), Velizar Dimitrov, Zadi (Petar Dimitrov 84).
Subs Not Used: Kutchoukov, Olegov, Zafirov, Ivan Ivanov, Matic.
Goals: Iliev 16.
Ref: Wolfgang Stark (Germany).