Perhaps the afternoon onslaught of slashing rain had washed West Ham clean of their remorse, a year on from their Europe League semi-final defeat by Eintracht Frankfurt. Perhaps this Europa Conference League semi-final with AZ Alkmaar is just a step down in competition. Either way, its first leg marked a liberating step forward for West Ham, who battled from behind to emerge 2-1 winners at home on Thursday. The 2006 FA Cup final, a soul-splintering affair for the Hammers, remains the closest the club has come to a trophy in over 40 years, and while that shattered spirit is arguably still to be restored, its fragments seemed to glint when West Ham reached the final four of the continent’s second competition 12 months ago. And again they gleamed on Thursday, in the soaked, steel silo of the London Stadium, where the reserves of fans’ faith were rewarded by a second-half rally. While West Ham's narrow, nervy win over Manchester United on Sunday was about West Ham maintaining their place in the Premier League, this game was about David Moyes' side mentally measuring themselves against last year's team, which was physically more formidable but proved emotionally fragile against Frankfurt. Sixty thousand home fans offered emotional support on this occasion, soundtracking the scenes before them as they had done in the knockout ties of last season, rattling the bolts of this silo with each roar, while the Alkmaar faithful bounced and buoyed their on-pitch avatars. Early on, however, exuberance was Alkmaar's best offering, and even that left them too exposed. West Ham were eager to exploit the space they saw – whether Lucas Paqueta was pirouetting into it or Michail Antonio was marauding through it. The home team failed to capitalise on early opportunities to establish a lead, however, with Jarrod Bowen misjudging the angle of a header and the timing of an incoming cross. Still, West Ham were the stronger and slicker side and nearly struck first when Said Benrahma forced Mathew Ryan into a desperate, fingertip save with a curving, first-time effort. The rising pressure around the Alkmaar goal was greeted by raucous reactions in the stands. The excitement turned to aggravation, though, as the home fans and players vented over what they perceived to be an unpunished push on Paqueta. His fall seemed theatrical, and against the odds, Alkmaar closed the first act of this semi-final with a goal. The visitors, apathetic to West Ham's appeals, picked out Tijjani Reijnders in an embarrassment of space, and his rifled shot bounced over the gloves of a despairing Alphonse Areola. West Ham had little time to spare in the second half, but Alkmaar felt they had plenty to waste. That was until they forfeited their advantage when Ryan clawed at Bowen's face to prevent a close-range header, giving away a penalty and receiving a booking. The noise, as Benrahma whipped his spot kick beyond Ryan, was brutal. So was West Ham's oppressive pursuit of a second goal to transform this tie, or at least reshape it into its intended outcome, with 20 minutes remaining. Within ten, the oppression had paid off. Nayef Aguerd's header was cleared off the goal line but only as far as the looming Antonio, who stabbed the ball home to puncture Alkmaar's hopes of leaving London with a lead. It was in the final throes of this game that West Ham demonstrated how vital those goals had been in unshackling the chains of their last European semi-final. Courtesy of interplay between Paqueta, Benrahma, Declan Rice and substitute Danny Ings, Moyes' side exhibited the kind of free-flowing football that has eluded them too often this term. Next week, West Ham travel to the Netherlands to cleanse themselves of the spirit of Frankfurt. They will be carried by a soul that is stirring with each of these European nights. Read More Erik ten Hag reveals David De Gea contract stance after costly mistake at West Ham Manchester United’s fragility allow Liverpool back into the battle for Europe West Ham vs Manchester United LIVE: Premier league result and reaction Declan Rice among West Ham players expected to be fit to face Manchester United Six clubs, only three survive: Who can escape the Premier League relegation fight Record-breaker Erling Haaland makes the extraordinary look predictable again