Birmingham’s unbeaten start to the season ended at St Andrew’s as slick Cardiff strode to a 3-1 victory and passage into the third round of the Carabao Cup for the first time since 2014.

It took the Bluebirds just three minutes to open the scoring as Karlan Grant burst away from Marcel Oakley down their right. The former West Brom man rolled a pass into Rubin Colwill’s path and the 21-year-old stroked home first time.

Blues’ best moment of the first period came in the 24th minute when Andy Rinomhota was booked for bringing down Juninho Bacuna from behind. The Curacao international picked himself up and curled the free-kick over the wall only to see Alex Runarsson superbly tip on to the bar.

The hosts’ task became even more difficult in the 56th minute when Lukas Jutkiewicz was sent off for serious foul play after a late challenge on Mahlon Romeo.

Cardiff doubled their lead 12 minutes later when Ollie Tanner picked out Colwill in the penalty box and the youngster laid back for Ryan Wintle to strike unerringly into the bottom corner from 20 yards.

Birmingham made a contest of it with 20 minutes to go as Manny Longelo threaded a pass into the path of Scott Hogan who finished neatly between the goalkeeper’s legs, but Erol Bulut’s men settled it with a back-post finish from Kion Etete four minutes into added time.