Berbatov, playing in the middle of United's three-pronged attack, fed the 20-year-old superbly with a ball that required little more than a cool head and a firm strike to send it beyond Kapini. Down the other end, Lindegaard had to react smartly down by his near post to prevent Ayanda Dlamini from restoring parity almost immediately. The same tricky AmaZulu forward wasted a much easier chance just before the break at the conclusion of a sustained period of pressure from the home side.
It wasn't the final highlight of the first half, though. That honour fell to Berbatov, who drew an acrobatic save from Kapini with an outrageous volley from 18 yards, direct from Robbie Brady's corner.
The anticipated raft of half-time substitutions never materialised (AmaZulu made two, Vermijl replaced Veseli) so the Bulgarian continued to torment the South Africans in the second period. One early shot was cleared off the line; another drew yet more goalkeeping heroics.
Lindegaard's battle with Dlamini also resumed at the other end, with the Dane diving to keep out an effort bound for the far corner. An even better stop denied substitute Josef Lekata from close range.
There was mass confusion just after the hour mark when the referee pointed to the penalty spot after Blackett, on for Brady a few minutes earlier, tumbled inside his own box under a clumsy challenge from an AmaZulu forward. Sense prevailed after United's protestations, however, and the Reds escaped unscathed.
Petrucci rattled the crossbar from distance in the game's closing stages before Kagawa's eventual inclusion on 89 minutes earned the biggest cheer of the night.