Sam Allardyce's side were moments away from earning a creditable draw against the current Swiss champions in the final game of their Uhrencup adventure.
A late Junior Stanislas penalty appeared to have salvaged a draw for the Hammers, who had fallen behind to a 52nd minute Pak Kwang Ryong strike.But a blunder by Julien Faubert saw the Swiss side awarded a penalty in injury time, which was subsequently converted to leave the Hammers pointless from their two tournament outings following Monday's defeat to Young Boys by the same scoreline.
Allardyce's side - captained for the first time by debutant Kevin Nolan - were second best for much of the game although his starting XI for the opening game of the Championship season against Cardiff next month is unlikely to resemble the team that started here in Grenchen.
With Scott Parker and Robert Green 'rested' once again, a number of youngsters were given further opportunity to prove themselves worthy of a position in the first team squad next term.
Marek Stech, Junior Stanislas, Robert Hall and Freddie Sears all started, with more experienced squad members such as Luis Boa Morte, Mark Noble and Carlton Cole omitted - although the latter, who is in protracted talks with Stoke, did make a late cameo as replacement for Abdoulaye Faye.
Faubert's faux pas: Julien concedes a 93rd-minute penalty (image from fcb.ch)
FC Basel 2 West Ham United 1: Match Facts
West Ham United: Stech, Spence (Faubert 46), Reid (Faye 46, Cole 77), Tomkins, Ilunga (Brown 62), Sears (Montano 46), O'Brien (Lee 46), Nolan (Boa Morte 46), Stanislas, Hall, Piquionne.
Subs not used: Boffin, Hernani, Moncur, Nouble.
Goals: Stanislas (pen 75).
FC Basel: Colomba, Ajeti, Voser, Xhaka, Shaqiri, Abraham, Frei, Cabrai, Wieser, Zhaka, Pak.
Subs: Herzog, Park, Dragovic, Schurpf, Huggel, Yapi, Steinhofer, Zoua, Buess, Paiva.
Goals: Pak (53), Yapi (pen 90+3).
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