David Moyes celebrated the best moment of his career after West Ham won their first major trophy in 43 years by beating Fiorentina in the Europa Conference League final, while Declan Rice insisted his future was not yet decided after captaining the side to a dramatic win.

Jarrod Bowen scored the winner in the 90th minute, sparking wild scenes at the Eden Arena in Prague, and Moyes beamed after the final whistle. West Ham’s manager was delighted to win the first major trophy of his career.

Related: Jarrod Bowen strikes at the last to earn Conference League glory for West Ham

“This is fantastic,” Moyes said. “I’ve had a long career in football and you don’t get many moments like this. Thankfully tonight we’ve had a great time and we got the result we wanted. The game probably didn’t go to plan the way we wanted. But in the end, winning finals is the important thing.

Moyes, who has been under severe pressure this season, was asked if it was the proudest moment of his career. “I would have to say so,” he said. “The moments you get to celebrate with your family and everybody here, and to win in the last two minutes in the game, it’s a great feeling.”

West Ham took the lead through Saïd Benrahma’s penalty but Giacomo Bonaventura pegged them back. Extra-time beckoned and they eventually found a way to win only their second European trophy.

Rice was ecstatic after captaining the side to victory and following in the footsteps of Bobby Moore, who wore the armband when West Ham won the Cup Winners’ Cup in 1965. The midfielder is expected to leave this summer, with Arsenal favourites to sign him, but Rice insisted: “It is not a goodbye yet. There is loads of speculation but nothing has happened. I am still a West Ham player. I have still got two years left on my contract. I love every minute of it. You can see the smile on my face. It is not about that tonight. It is about us celebrating and that’s what I am going to do now.

“It means everything. The lads have been so on it, but I’m not only happy for the fans and the manager but the staff. I’m just so, so happy. I absolutely love this club, they’ve taken me in as one of their own. I am just so happy.”

West Ham could face punishment from Uefa after their fans threw plastic cups on to the pitch during the first half. One missile struck Fiorentina’s captain, Cristiano Biraghi, and left him with a bloodied head.

The club released a statement condemning the trouble: “West Ham United unreservedly condemn the behaviour of a small number of individuals who threw objects on to the pitch during tonight’s Uefa Europa Conference League final.

“These actions have no place in football, and do not in any way represent the values of our football club and the overwhelming majority of our supporters, who have behaved impeccably in Prague this week and throughout our last two seasons in European competition.

“We will work with the police and other stakeholders to review the incidents and act against anyone found guilty of an offence. In line with our zero-tolerance approach, anyone identified will have their details passed to the police and will be given an indefinite ban and therefore be unable to enter London Stadium and travel with the club. There is no place for this kind of behaviour at West Ham United.”

West Ham confirmed they will hold a parade in east London on Thursday night.