Trevor Sinclair netted a second-half winner for Kevin Keegan's men after Javier Saviola had cancelled out Nicolas Anelka's opener.
Former City stars Shaun Goater and Ali Bernabia were given tremendous farewells from the City fans with Benarbia playing 25 minutes before being replaced by Eyal Berkovic.
Anelka opened the scoring on 34 minutes capitalising on a misplaced pass from City target Michael Rieziger before driving the ball past Rustu Recber.
Barcelona drew level on 57 minutes with Argentine ace Saviola netting his second goal in the Spanish side's tour of England - having scored against Leicester City on Friday night.
Sinclair grabbed the winner for City on 67 minutes with a fine downward header to cap a memorable day for City's fans.
Totthenham Hotspur handed a home debut to South African captain Mbulelo Mabizela in their match against Sporting Lisbon.
After toppling Manchester United in midweek, the Portugese side were attempting to claim a second Premiership scalp but the contest ended 0-0 in intense heat at White Hart Lane.
David Thompson struck the only goal of the game as his 25-yard volley was enough to give Blackburn Rovers a 1-0 victory over Italian side Chievo Verona at Ewood Park.
Leeds United's miserable pre-season was completed by a 2-0 defeat to Irish side Shelbourne in the Dublin tournament, which means that Peter Reid's charges have failed to win a single game in their build up to the new campaign.
It was a better day for former Elland Road boss David O'Leary, as his Aston Villa side won the Dublin tournament with a 6-0 thumping of St. Patrick's Athletic.
Juan Pablo Angel and Marcus Allback struck doubles while Peter Whittingham and Thomas Hitzlsperger also got their names on the scoresheet.
It was mixed news for Everton in Colin Harvey's testimonial against Italian side Bologna at Goodison Park.
Richard Wright successfully came through his second appearance in 48 hours but striker Kevin Campbell limped off with an injury to his right leg.
David Moyes will be hoping Campbell will be fit for the start of the season as Wayne Rooney is missing through injury while Duncan Ferguson is suspended.
The Toffees did run out comfortable 3-0 winners - thanks to first half goals from Tomasz Radzinski and Nick Chadwick - while Mark Pembridge rounded off the scoring with a 20-yard effort soon after the break.
Fulham clinched a 2-1 victory at home to Real Mallorca with Chris Coleman giving debuts to full backs Jerome Bonnissel and Moritz Volz.
The Spanish side took the lead with a close-range strike from Samuel Eto'o but Luis Boa Morte levelled things up just after the half-hour mark and a fine team move that was finished off by Steed Malbranque gave Coleman's side the win.
