ATLANTA -- The Atlanta Hawks have had so many injuries and illnesses that they may not know who will be on the floor until tipoff.

They can count on one thing when they're playing the Magic -- a win.

Ivan Johnson came off the bench to score a season-high 21 points and added 10 rebounds as Atlanta beat Orlando for the 10th straight time, 97-88 in Philips Arena, in a game between short-handed teams.

Even with their 27th different starting lineup, the Hawks (41-33) found a familiar result while sweeping their four-game season series with Orlando to move into fifth in the Eastern Conference, a half-game ahead of Chicago.

Devin Harris, who missed the three previous games with a sore foot, scored 13 of his 17 points in the fourth quarter as Atlanta gradually created breathing room.

The burly, soft-spoken Johnson scored 10 points in each half beginning with a thunderous dunk late in the first quarter.

"It was fun tonight. I got a lot of work in," he said after playing a season-high 34:28. "It gets me going real good (to get an early dunk). It helped me stretch my legs out. I'm getting old."

Atlanta coach Larry Drew gave Johan Petro a rare start at center as Al Horford missed his second straight game with a stomach illness, and the Hawks earlier announced that reserve center Zaza Pachulia will have season-ending surgery on his right Achilles tendon.

Drew started Johnson in the second half.

He chuckled after his comment about getting old (he'll be 29 on April 10), and then added, "Somebody had to step it up with Al out tonight."

Actually, several Hawks fit that description.

Harris caught fire in the fourth quarter, and backup guard Shelvin Mack -- recently signed for the rest of the season after bouncing around the D-League -- added eight points, a couple assists and solid defense off the bench.

Mack played 20:56 in large measure because the Hawks were missing rookie John Jenkins (concussion) one night after he scored a career-high 19 points in a loss at Boston.

"Ivan was the man tonight," Drew said. "And Shelvin Mack is kind of like a mini-Ivan with his energy."

There were nine lead changes in the first half, but after Josh Smith grabbed an offensive rebound and scored at the buzzer to give Atlanta a 45-44 halftime lead, the Hawks never trailed again. Smith had 21 points, nine rebounds, three blocked shots and a couple steals.

Orlando's Beno Udrih hit a jumper with 3:49 left in the third quarter to knot the game at 55. Atlanta's Anthony Tolliver countered with a jumper, and Atlanta led the rest of the way.

Udrih, who was filling in for Orlando point guard Jameer Nelson (sprained ankle), led the Magic with 20 points and eight assists.

Orlando also was missing leading scorer Arron Afflalo (strained right hamstring), but center Nikola Vucevic had 17 points and 15 rebounds in his first game after missing five because of illness and concussion.

The Magic were competitive while Maurice Harkless scored 17, and D-League veteran Tobias Harris added 11 points and 10 rebounds.

Harris, though, was harassed chiefly by Smith into a 5-for-18 shooting night. Orlando also struggled at the free throw line on a 16 for 27 (59.3 percent) while losing for the 11th time in 13 games.

"(Smith) has great length and athleticism," Orlando coach Jacque Vaughn said. "The Hawks have big, strong, physical guys that make it tough to score on them. If it's not Horford or Pachulia, then it's Ivan Johnson.

"We're putting together quarters, we're putting together halves. That will eventually add up to putting together games and consecutive games."

Atlanta grew its lead to 14 points on a three-point play by Johnson with 7:14 left in the game.

Game notes
Atlanta's Kyle Korver made a 3-pointer in the second quarter, the 67th straight game in which he's hit at least one trey. The former Creighton star is one game from tying Reggie Miller (68) for the fourth-longest such streak in NBA history. Only Dana Barros (89), Michael Adams (79) and Dennis Scott (78) put together longer runs than Miller. ... The Hawks were also missing guard-forward DeShawn Stevenson (knees). He was unavailable because he doesn't play in back-to-back nights. ... Atlanta is already without guard Louis Williams, who suffered a season-ending knee injury a couple months ago, and the Magic have been without second-leading scorer Glen Davis (fractured foot) for two months.