Another Mohamed Salah masterclass helped Liverpool take control of their Champions League semi-final - but two late Roma away goals gave the Italian side a glimpse of hope for the second leg.
Liverpool, who last reached the final in 2007, repeatedly breached the visitors' naively high defensive line and scored five times in the opening 68 minutes at a raucous Anfield on Tuesday, according to a BBC report.
Salah, who has now scored 43 goals since his summer move from Roma, scored twice and assisted two other goals.
He curled his first into the top corner from the edge of the box - then clipped the ball over Alisson for a second.
Salah then ran down the right and squared for Sadio Mane to make it 3-0 - before doing the same to set up Roberto Firmino.
Liverpool then became only the second team to score five goals in a Champions League semi-final match when Firmino headed in James Milner's corner.
With his side leading 5-0, Reds boss Jurgen Klopp took off Salah - and Roma gave themselves a chance for next week's return leg at the Stadio Olimpico.
First Edin Dzeko lashed home from Radja Nainggolan's pass, then Diego Perotti put a penalty into the top right corner after Milner handled Nainggolan's shot.
And Roma need only look to the last round for inspiration - they lost the first leg in Barcelona 4-1 before winning 3-0 in Italy to progress on away goals.
A repeat of the latter scoreline this time would take them into the final against Bayern Munich or Real Madrid.
Prior to Roma's late goals, the one sour note for Liverpool was the sight of Alex Oxlade-Chamberlain leaving the field on a stretcher. Klopp said later the England midfielder "probably had a really bad injury".