NAPLES, Italy (AP) — Liverpool has a long way to go to regain the form that took it to the final of last season’s Champions League.

Napoli overwhelmed the English power with three first-half goals in a 4-1 win in the opening round of group play on Wednesday.

Piotr Zielinski converted a penalty, André-Frank Zambo Anguissa doubled the lead after the half-hour mark and substitute Giovanni Simeone — the son of Atletico Madrid coach Diego Simeone — scored on his competition debut just before the break.

Zielinski added another two minutes after the break before Luis Díaz finally pulled one back for Liverpool on a counterattack in the 49th.

“We were miles too open. You can’t come to a place like this and not stay compact,” Liverpool left back Andy Robertson said. “Too many times they turned and had big open spaces to run at.

“Unfortunately, we deserved this result, the way we were wide open. We need to wake up, and quickly.”

Liverpool has now failed to win all four of its visits to the Stadio Diego Armando Maradona, while coach Jürgen Klopp dropped to 0-4 in his career in Naples. Klopp was sent off during a loss while coaching Borussia Dortmund in 2013, then was at the helm for Liverpool defeats in 2018 and 2019.

Ajax beat Rangers 4-0 in the other Group A match earlier.

Liverpool has started the Premier League season with just two wins from six games. Napoli is unbeaten in five Serie A matches and leads the league with 12 goals scored despite the offseason departures of captain Lorenzo Insigne, all-time leading scorer Dries Mertens and defensive stalwart Kalidou Koulibaly.

The recent form of the two teams held as Napoli got off to a blistering start.

In the opening minute, Victor Osimhen beat Liverpool’s offside trap and dribbled around goalkeeper Alisson before striking a shot off the outside of the post from a sharp angle.

Four minutes later, Zielinski sent Alisson the wrong way with his spot kick after Liverpool captain James Milner deflected a shot from the Poland midfielder with his arm.

Osimhen then won another penalty after Virgil van Dijk stepped on his boot but Alisson blocked the ensuing spot kick from the Nigeria center forward.

Zielinski turned provider for Zambo Anguissa, who finished off a give-and-take with the Pole to make it 2-0.

Simeone, who had come on for an aching Osimhen, tapped in a cross from Khvicha Kvaratskhelia, the 21-year-old Georgia winger who has been tearing up Serie A with four goals in five matches. Kvaratskhelia dribbled by two players on the left flank before setting up Simeone perfectly.

Zielinski’s second came on a rebound of his own shot after Alisson failed to collect.

“It was almost the perfect match,” Zielinski said. “We don’t know how far we can go from here.”

Liverpool, which lost last season’s final 1-0 to Real Madrid, is sorely missing departed forward Sadio Mane, who transferred to Bayern Munich. Injuries are also hitting hard in central midfield, while fourth-choice Joe Gomez looked rusty at center back.