Anthony Ujah's first-half double helped Werder Bremen come from behind to beat West Ham 2-1 at Upton Park.
Diafra Sakho put Slaven Bilic's side ahead in Sunday's friendly, but Ujah equalised soon after as Adrian failed to deal with his long-range effort.
The striker then put the Bundesliga side in front in the 31st minute with a well-taken goal that proved enough to claim the win.
West Ham started well and were rewarded in the 19th minute when Sakho swept home Dimitri Payet's cross from the right.
The lead proved short-lived, though, as a minute later Ujah's effort from 25 yards went straight through Adrian.
Ujah struck again just after the half-hour mark when he took a neat touch away from James Tomkins in the penalty area and placed his shot across Adrian into the bottom right-hand corner.
Adrian was replaced by Raphael Spiegel at half-time and he did well to palm away Felix Kroos' volley high to his left.
At the other end, Assani Lukimya-Mulongoti got a crucial touch on a Sakho effort that the home fans thought had gone in as it rippled the side-netting.
That proved West Ham's best chance to get back in the game and Bilic's men will now turn their focus to Thursday's trip to Romania to face Astra for the UEFA Europa League third qualifying round second leg, with the tie locked at 2-2.
‘Sir Alex told Van Persie to watch my goal back at Anfield for some shooting tips! It was a beautiful goal, though. It’s a shame that I didn’t do it more often’: Manchester United cult hero recalls stunning strike against Liverpool
‘So many times when we played Manchester United, arguments would start before the first whistle had even blown – the players would try to kill each other with their eyes’ Former Arsenal star remembers famous Premier League rivalry
