The City winger struck after 20 minutes, with a stunning individual effort at the Ullevaal Stadion.
Collecting the ball on the right of the Czech box, Bobb skipped inside one challenge and past another in one delightful shimmy before drilling a low left-foot shot into the bottom right corner of the net.
Erling Haaland was a constant threat for the hosts but David Zima’s powerful header levelled the scores on 36 minutes.
Haaland saw a shot go wide after good work by Martin Odegaard on 55 minutes.
Bobb and Haaland’s evening ended on 75 minutes when they were both substituted.
Gradually, the Czech Republic took control of proceedings, and five minutes from time, Antonín Barák scored a free kick to give the visitors a 2-1 win.
Overall, it was a fairly quiet evening for City stars.
Nathan Ake got a useful 90 minutes under his belt as Netherlands thrashed Scotland 4-0 in a friendly.
Goals from Reijnders (40’minutes), Wijnaldum (72’minutes), Weghorst (84’minutes) and Malen (86’minutes) sent the Scots packing as Ake won cap No.43.
Elsewhere, Rodrigo was an unused sub as Spain were beaten 1-0 by Colombia at the London Stadium.
The City anchorman was rested for what was La Roja’s first ever loss to the Colombians - Crystal Palace defender Daniel Munoz scoring the winner on 61 minutes.
Finally, Argentina beat El Salvador 3-0 in Philadelphia with Julian Alvarez also an unused sub as the world champions warm up for their Copa America defence this summer.
Spurs defender Cristian Romero opened the scoring in the 16th minute with Chelsea’s Enzo Fernández adding a second the 42nd and Tottenham’s Giovani Lo Celso made it a Premier League clean sweep by grabbing a third in the 52nd minute at Lincoln Financial Field.
