Liverpool FC have officially opened the stadium's new Main Stand, increasing the overall capacity to 54,074.
The £100m expansion work has added a third tier for supporters, boosting Anfield's crowd capacity by about 8,500.
Work began on the stadium last year and the club said it marked another "incredible chapter".
The expansion work is part of a wider £260m regeneration of the Anfield area of the city.
The redeveloped stand now houses about 20,500 seats and is the new home for the Hillsborough memorial.
Manager Jurgen Klopp said "it's so impressive" and "one of the nicest stands" he has ever seen in his life, adding that it "should be an advantage" for the team.