Kumble also heaped praise on Jean-Paul Duminy, who scored an unbeaten 99 to see the Cobras through.
"When you have 180 on scoreboard, it's always disappointing to lose. JP Duminy batted really brilliantly. We dropped number of catches that might be one of the reason, but there are other things to be looked after," Kumble said after the match.
"The bowl was coming lot quicker on this pitch. We thought that the pitch may play slower and it will spin later, but Duminy put up a great fight," he said.
Asked why he did not hand over the ball to experienced Jacques Kallis in the crucial last over with Cobras needing nine for victory, the leg-spinner said, "I thought slower ball will work and that's why I gave the task to Vinay [Kumar], but it didn't work."
Meanwhile, his counterpart Andrew Puttick said despite the shaky start, he was confident of chasing down the target.
"We were confident of chasing the target. We should have restricted them much earlier. We had a bad start, but Duminy was superb with the bat. If you get one batsman to play throughout the innings, then you can chase any target," he said.
Man-of-the-match Duminy said looking at the big target, he decided to go for all-out attack as it was the only way the Proteas side could have won the match.
"Target of 180 was always big and we have to chase it fast and I have only that thing in my mind," he said.
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