Côte d’Ivoire’s 1-0 victory against Ecuador showed their World Cup ambitions are genuine, the side’s manager Emerse Faé said, after Amad Diallo’s 90th-minute goal secured a winning start to their campaign on Sunday at the Philadelphia Stadium.

The Ivorians have impressed since booking their place at the finals in the US, Canada and Mexico, beating South Korea and Scotland in March and winning 2-1 away against France last week.

Fae’s youthful attack, including the highly rated 19‑year‑old winger Yan Diomande, was tested by an experienced Ecuador defence featuring Paris Saint-Germain’s Willian Pacho ‌and Arsenal’s Piero Hincapié, ‌shielded by the Chelsea midfielder Moisés Caicedo.

“We came to the US for this, and we came here ‌with ambitions, with high hopes,” Fae told reporters. “We don’t want to just have visited the US and have to go back, so everything is going well for now.

“We’ve beaten France. We are starting this competition well against Ecuador, a very tough team, but we managed to come into our own and won the match. This shows that our team has acquitted ‌itself well.””

Ecuador’s Piero Hincapié goes down in dramatic fashion as he battles for the ball with Côte d’Ivoire’s Guéla Doué. Photograph: Petr David Josek/AP

With the four-time champions Germany favourites in Group E, this match could prove decisive in the battle for second place. Côte d’Ivoire are appearing at the World Cup finals for the first time since 2014 and have never reached the knockout stages.

Diallo’s first-time finish from Wilfried Singo’s cross gave the Ivorians their first World Cup victory against South American opposition and halted Ecuador’s unbeaten run at 19 matches. It also put a bow on the RB Leipzig star Diomande’s dazzling performance as the Elephants pulled level on points with a Germany side that thumped Curaçao 7-1 in their opener in the group’s earlier game.

A packed Philadephia Stadium hosts Côte d’Ivoire v Ecuador. Photograph: Darrian Traynor/Getty Images

The Ivorians, who have the youngest squad at this World Cup finals tournament, looked to be running out of ideas before Singo found space surging up the right from his defensive post. His cross reached Diallo in stride, with the 23‑year‑old Manchester United player deftly guiding ‌it into the bottom left ‌corner to give the West Africans a dream start ‌to their first World Cup finals appearance since 2014.

Ecuador’s best first-half chances came from Côte d’Ivoire’s casual defending. John Yeboah and Alan Minda struck the bar in the 23rd and 30th minutes respectively. But it was Côte d’Ivoire who looked better in possession, with Diomande terrorising Ecuador’s left side.

In a match played within driving distance of more than 600,000 Ecuadorian Americans estimated to live in New York and New Jersey, La Tricolor fans brought the atmosphere but left disappointed.