McDermott's side have only lost once since Boxing Day, a 3-1 defeat at Tottenham, and have pulled themselves from the foot of the table to sit two points clear of the relegation zone.
The Royals have become the masters of late goals and it was no different against Sunderland as Kebe added to his opening goal on seven minutes with a dramatic winner five minutes from time.
The Malian took his first goal with aplomb but it was his match-winning header that McDermott felt epitomised his effort. "Jimmy Kebe is becoming phenomenal in the air," he said.
"I was so pleased for him because he such a brave player both physically and mentally.
"He wants to get on the ball and I think the first goal was fabulous. He wins headers and is good in the air, that was a great finish today. Ian Harte has put it in there and Jimmy has had to finish it off and he was brave."
Sunderland slipped to 12th with defeat at the Madejski Stadium after it looked like Craig Gardner's first-half penalty would be enough to secure a point for Martin O'Neill's side.
The Black Cats had a couple of chances of their own to claim the victory but O'Neill was ultimately left riled by Reading's late goal.
"Naturally I'm disappointed to concede so late in the game, particularly on the back of a couple of really good chances we had ourselves," he said.
"I thought Reading started better than us and got a goal in front but we started to come into the game a bit more before we scored the penalty."
Source: PA
Source: PA