With one touch to a gather a sublime pass from Lucas Paqueta and enough power in his legs to summon another burst of speed, Bowen powered into the penalty area and squeezed a low shot beyond goalkeeper Pietro Terracciano as he dashed from his line.
The ball clipped Terracciano’s legs but bounced on, into the net, in the 90th minute. Bowen wheeled away and a night of tension, irritation and aggravation transformed into sheer jubilation.
It had been a test of nerve and temperament as much as anything against Fiorentina, who ran through the full repertoire of Italian dark arts. Moyes claimed on the eve of the game that West Ham were more mature than last year, when they reached the semi-finals of the Europa League, and his players proved him right.
They passed their tests and Paqueta and Bowen combined for a flash of quality, just as the final seemed destined for extra time. It was the second time they had led. Said Benrahma put them ahead from with a penalty in the 62nd minute, but the Italians were level within five minutes.
This time, West Ham protected the lead through eight nervy minutes of stoppage time to become Europa Conference League champions, their first trophy since the FA Cup in 1980, their first in Europe since 1965. The first won abroad in their history.
It was a first for boss Moyes, who could not have looked any prouder as he gripped his gold medal and shook it towards the battery of photographers, and it was the perfect way to go out for captain Declan Rice, who fought back the tears as he went through his TV interviews and fans sang his name.
Thousands of West Ham supporters had poured into Prague and the lucky 5,000 with tickets will never forget they were there for the occasion because the occasion was far better than the match itself, which was, for the first hour, a terribly disjointed affair devoid of fluency.
Fiorentina boss Vincenzo Italiano admitted his team would deploy cynical tactics, pressing high and making smart fouls to stop the counterattack, but this contest was littered with his players rolling around and exaggerating injuries.