Andy Carroll netted a double in vain as West Ham were beaten 3-2 by Serie A champions Juventus in a game to mark the official opening of the London Stadium.
A quickfire double from Paulo Dybala and Mario Mandzukic put the visitors in control in the East End sunshine, with the Hammers far inferior to their illustrious opponents.
Carroll soon got the hosts back in it on a sun-drenched day at their new home, bundling the ball into the net in typically combative style, before heading an equaliser in the second half.
Hammers fans will have been pleased to see Dimitri Payet get his first minutes of pre-season, while record signing Gonzalo Higuain made his Juventus bow as a substitute, but it was another replacement in Simone Zaza who won it late on for the Old Lady.
West Ham in fact played a first competitive game at their new home when they beat Domzale in a Europa League qualifier last week but this was set to be the big curtain-raiser for a new era and supporters were treated to a carnival atmosphere.
That mood was dampened slightly, as a strong-looking Juventus team took charge early on, racing into a two-goal lead.
Moments after Enner Valencia saw his effort come back off the woodwork, a superb knockdown from Mandzukic picked out the run of Dybala, who took a touch and finished with his left foot in impressive manner after 18 minutes.
Before the supporters had re-taken their seats, the Serie A champions were two goals to the good, with the same combination linking up to devastating effect. This time Dybala returned the favour, slipping the ball in for Mandzukic for slot home.
With the visitors looking in fine fettle, Carroll took it upon himself to get his side back in it, getting on the end of a Sam Byram cross in the 34th minute, reacting quickest as his header was saved by Gianluigi Buffon to bundle the ball home.
The Hammers lived dangerously as a goalmouth scramble somehow didn't result in a Juve third, the crossbar and a Carroll goal-line clearance coming to the rescue.
After the break, Carroll continued to be a menace as Higuain laboured after coming off the bench down the other end, and the combative hitman soon found a leveller, this time attacking a Mark Noble free-kick, and powering a header into the bottom corner.
A raft of changes disrupted the flow of the game, but Payet's introduction got the crowd off their feet once more.
However, as we seemed to be heading for a penalty shoot-out, Zaza netted the winner out of nowhere. The Italy international brought the ball down superbly out of the air, stole a march of Reece Oxford and finished clinically with his left foot.