Despite the result at the Mercedes-Benz Arena, Hoeness praised his team’s attitude and insisted the tie was still alive ahead of next week’s return leg in Portugal.

“First of all, congratulations to Porto on their victory in the first leg,” Hoeness said afterwards. “We started the game very well, had good energy and created a lot of chances in the opponent’s half.

“Unfortunately, the momentum shifted after Porto hit the crossbar. What frustrates us is the eight to ten minutes in which we briefly lost our composure and gave the ball away too easily.”

Stuttgart began brightly, pushing forward down the flanks with Jamie Leweling causing early problems with his pace. The winger forced Diogo Costa into a save after 17 minutes, while efforts from Bilal El Khannouss and Ermedin Demirovic tested the Porto defence.

But the visitors quickly turned the match in their favour. After striking the crossbar in a warning moment, Terem Moffi opened the scoring on 21 minutes. The forward capitalised on a loose ball, combined with Borja Sainz and curled a precise finish past Alexander Nubel.

Porto doubled their advantage before the half-hour. A defensive lapse allowed Zaidu Sanusi to deliver a cross that found Rodrigo Mora, who tapped in from close range.

Stuttgart responded before the interval when Deniz Undav produced a superb volley to bring the home crowd back into the contest.

Hoeness was pleased with how his players reacted after the difficult spell.

“After that, the lads regrouped quickly, came back, scored the equaliser and gave Porto a run for their money for a long stretch,” he said. “Despite the defeat, I want to compliment my team on a courageous performance.”

The second half became a tactical battle as Porto slowed the tempo and managed the game intelligently. Stuttgart thought they had levelled on 72 minutes when Angelo Stiller bundled the ball into the net, but the goal was ruled out for offside after a VAR review.

Late chances from El Khannouss were kept out by Costa, leaving Stuttgart trailing heading into the second leg at the Estadio do Dragao.

Hoeness insisted the tie remains wide open. “It was only the first of two matches,” he said.

Before travelling to Portugal, Stuttgart must quickly refocus on domestic duty with a crucial Bundesliga clash against RB Leipzig on Sunday.

France World Cup winner Antoine Griezmann retires from international football