Smith also grabbed nine rebounds and Johnson, who came off the bench, hauled down 10 boards as the Hawks won despite the absence of forward Al Horford, who missed his second straight game because of illness.
Devin Harris contributed 17 points and six assists for the Hawks.
The Magic got 20 points from Beno Udrih en route to their 20th loss in 28 road games.
Maurice Harkless scored 17 points and Nikola Vucevic returned from a five-game concussion absence to supply 17 and 15 rebounds for Orlando.
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