How do you replace 204 goals in 332 games? The Jürgen Klopp way was to wait until the 56th minute and throw on Cody Gakpo and Darwin Núñez to fill the void left by Mohamed Salah.

It worked. A quarter of an hour later Liverpool had transformed a 1-0 deficit into a 2-1 victory, the Gakpo‑Núñez combo crafting the winner. Yet until their introduction this semi-final first leg against Fulham was the oddest of tales.

Related: Gakpo caps Liverpool fightback to gain Carabao Cup first-leg edge over Fulham

Becalmed at Anfield: it is supposed to be the fate of visitors, not of Liverpool. Especially not a Klopp vintage who are Premier League leaders, who began this match unbeaten in 14 games at their cathedral, 12 of these wins, with only Manchester United and Arsenal managing to avoid defeat here.

This, though, was the story until the 68th minute when Curtis Jones hit one in off Tosin Adarabioyo’s back and then Gakpo slotted home a cool flicked finish the missing Salah might have fashioned, the pinpoint delivery coming from Núñez.

Until their advent, this second outing since the loss of Salah on Africa Cup of Nations duty and a first following Trent Alexander‑Arnold’s knee problem had featured two other A-listers, Virgil van Dijk and Ibrahima Konaté, being too feeble, too often, in a rearguard also including a makeshift left-back – Joe Gomez – and Conor Bradley, a 20-year-old yet to play in the Premier League.

In the absence of Salah and Alexander-Arnold, Klopp did not need to see his captain culpable for Fulham’s opener, yet it was Van Dijk’s weak header that allowed Willian to dance in and score. Then moments later, a handoff on Andreas Pereira drew a yellow card. Rattled? A touch, as were Liverpool, whose shakiness will alert their main title rivals, Manchester City.

Van Dijk’s Liverpool CV shows a sweep of all domestic honours plus the Champions League, Uefa Super Cup and Club World Cup. Willian, previously at Arsenal and Chelsea, has also claimed every trophy available in the English game plus the Europa League: a more modest record than the Dutchman’s but, at 35, his strike and scampering presence along the left teemed with the vigour of a man a decade younger.

Klopp’s solution to the Salah problem had been, initially, Harvey Elliott, who was asked to probe in the “Mo-zone” on the right of a frontline that had Diogo Jota marauding centrally and Luis Díaz on the left. But this trident’s toothlessness was summed up by Liverpool’s best efforts coming from long range from a defender, Gomez, and a midfielder, Ryan Gravenberch. Later, when Jota was in on Bernd Leno’s goal he over elaborated and Adarabioyo hacked clear.

Fulham had been 3-2 up until the 86th minute of the Premier League meeting at this stadium in December before Waturu Endo and Alexander-Arnold goals undid them. Now, they inched towards a priceless advantage ahead of the second leg in a fortnight.

Klopp, though, did what all the best managers do: act decisively, by hooking Gravenberch and Elliott for Gakpo and Núñez. Yet before they sealed the win the Van Dijk‑Konaté axis was again fooled by Willian, the Brazilian forward’s ball slicing open Liverpool and putting Bobby De Cordova-Reid in for a chance that had Marco Silva stamping in frustration when he missed.

The Fulham manager had declared it was great fans could “dream” of a trip to Wembley. This defeat does not end the fantasy as his side saw enough holes in their hosts’ defence to encourage them in a clash that pitted the land’s second-highest major domestic cup winners in Liverpool (17) against a west London side yet to win a major honour.

The club by the River Thames have to rewind 49 years for their only final on these shores when an XI captained by Alan Mullery and containing Bobby Moore went down 2-0 against West Ham in the 1975 FA Cup final. So at Craven Cottage in 14 days’ time, the hope will be that this iteration can overturn the 2-1 deficit and bridge the gap to that Wembley day, and the 14 years since the sole other occasion Fulham were 90 minutes from glory.

That was the 2010 Europa League final when Roy Hodgson’s men took the Atlético Madrid of Sergio Agüero, David de Gea and Diego Forlan into extra time at Hamburg’s Volksparkstadion before Forlan’s second goal – after Simon Davies had equalised on 37 minutes – broke their hearts.

That year Fulham’s scalps in the knockout rounds were Shakhtar Donetsk, Juventus, Wolfsburg and Hamburg. In this list beating Juve 4-1 at Craven Cottage, having lost 3-1 at the Stadio Delle Alpi, courtesy of Clint Dempsey’s memorable 82nd-minute winner is the headline result. Knocking Klopp’s side out in the semi-final of England’s second-biggest cup would rank alongside the feat. Or even trump it.