Liverpool booked their place in the fourth round of the FA Cup as Lucas Leiva proved the unlikeliest of goalscoring heroes in a 1-0 win at Plymouth.
The Brazilian had not scored since finding the net in a Europa League tie against Steaua Bucharest in October 2010, but he provided the decisive touch of this third-round replay with an 18th-minute header.
League Two Plymouth came agonisingly close to an equaliser when Jake Jervis volleyed against the post 15 minutes from time and, although Divock Origi saw his late penalty saved by Luke McCormick, Liverpool move on to a home tie with Wolves in the next round.
The Premier League side chose to omit Joel Matip as the row over the defender's eligibility rumbles on.
Boss Jurgen Klopp felt he could not risk playing Matip with FIFA unable to say whether he is free to play after Cameroon tried to call him up for the African Nations Cup.
But Origi, Daniel Sturridge and Philippe Coutinho all started in a formidable looking frontline as Klopp named a stronger line-up than the one held by their Devon opponents on Merseyside 10 days earlier.
Plymouth only had 23 per cent possession at Anfield and the tie quickly developed a similar pattern as Liverpool set up camp in the Pilgrims' half.
Sturridge's shot lacked accuracy and Coutinho scuffed an inviting effort when well placed at the far post.
Liverpool also saw penalty appeals waved away after Sturridge fell under Oscar Threlkeld's clumsy challenge, but the visitors were ahead after 18 minutes.
Plymouth would have been bitterly disappointed by the nature of Liverpool's goal, while few - if any - could have predicted the identity of the scorer.
Lucas had scored only six goals in nearly a decade at Liverpool - and none for over six years - but it was the Brazilian who stole in unmarked at the near post to head home Coutinho's corner.
Moments later Lucas, the Liverpool captain for the night, stopped Ryan Donaldson from claiming an instant equaliser after Loris Karius had pushed out Graham Carey's well-struck drive.
It was a sign Plymouth were determined not to slip quietly from the FA Cup and the hosts played their best football of the entire tie as the Liverpool defence had to scramble on more than one occasion.
Trent Alexander-Arnold produced a timely tackle on Arnold Garita following good work by the lively Threlkeld, and Joe Gomez was booked for felling Jordan Slew as the pacey Argyle striker threatened to bear down on goal.
Liverpool needed the security of another goal but it was the hosts who started the second half as they had finished the first.
Carey was at the heart of an incisive one-touch move which ended with David Fox firing from distance and Karius gathering on his line.
The majority in a sell-out crowd of 17,048 were clearly sensing a way back for Plymouth.
But Liverpool slowly re-established control with Sturridge finding the side netting and Origi forcing a save from McCormick.
Klopp was relaxed enough to withdraw Coutinho and send on Harry Wilson for a Liverpool debut over three years after he eclipsed Gareth Bale to become Wales' youngest player.
But Liverpool had an almighty scare when Jervis was left unattended from Sonny Bradley's knock down to volley against the post with Karius beaten.
Origi failed to double Liverpool's lead after Yann Songo'o had fouled Alberto Moreno in the penalty area, sending his shot straight at McCormick.
But Plymouth can take pride from a committed performance safe in the knowledge that their FA Cup exploits this season have earned the club an estimated Â£1million.