Howard had 14 points and 13 rebounds after missing two games because of a sore knee, and Jameer Nelson scored 24 points to help the Magic beat perennial Western Conference contender San Antonio 90-78.
The win, coming at the front of a stretch that includes the Lakers on Saturday and Southestern Division leader New Orleans at home on Christmas, helped the Magic (20-6) stamp themselves as legitimate contenders. Orlando has won seven of its last eight games and leads Atlanta by 4 1/2 games in the Southwest Division.
"Sometimes things go your way," Nelson said.
Tim Duncan led the Spurs with 19 points.
The Spurs, down by 23 in the third quarter, used a 13-4 run to draw within six in the fourth quarter, but Nelson hit back-to-back baskets to give the Magic a cushion. Nelson scored 21 of his points in the second half.
"We've got to play with the great surge, because nobody believes in us, everybody doubts us," Nelson said. "We have to play for the fans, and each other, and everything will be fine."
Howard picked up his fifth foul halfway into the fourth quarter and went to the bench.
The schedule was not kind to the Spurs, the oldest team in the league with an average age of 29. San Antonio lost at New Orleans on Wednesday night, and the Magic came out looking to run on the weary Spurs.
"I knew coming in they were coming off a very tough back to back," Magic coach Stan Van Gundy said. "We wanted the pace fast."
The Magic took advantage, outscoring the Spurs 18-2 on the fast break in building a five-point halftime lead.
"Everybody gets tough back to back," Spurs coach Gregg Popovich said. "The timing wasn't great. Coming in at 3:30 [a.m.] wasn't good.
"Orlando will have something in its schedule where they'll have a god-awful back-to-back. It evens out in the end."
Orlando's next back-to-back matchup comes in mid-January, when its plays the Lakers and Nuggets on the road in consecutive nights.
The Spurs shot poorly in the first half. San Antonio made only 28 percent of its shots. Guard Tony Parker made only one of 10 shots, and Duncan was 2-of-7.
Orlando went on a 10-0 run early in the third quarter to take a 54-31 advantage. The Spurs didn't get closer than six points in the second half. San Antonio, using a smaller lineup, cut it to 71-65 on Parker's free throws midway through the fourth.
"They made shots when they needed to," Duncan said. "Jameer was great, obviously. He always seems to play great against us. They moved the ball well and hit big 3s to set us back."
"They really don't want us to shoot 3s," Nelson said. "Teams have to pick their poison. We have great shooters to take 3s. I'll continue to take the shots that are open."
The Magic have worked with an eight-man rotation much of the season, but injuries have forced them to dig deep on their bench. Nine players saw action against the Spurs, including seldom-used backup center Marcin Gortat.
Gortat had 16 points and 13 rebounds against Golden State last week in place of Howard. He had two points and three rebounds against the Spurs.
The Spurs (15-10) started 1-4, worst in team history, then won 14 of 20 games before Thursday. They've beaten only five teams with a winning record, and have lost two straight.
Spurs center Fabricio Oberto remained sidelined by a sore foot. He'd been out of the rotation, and played only 41 seconds against New Orleans on Wednesday. ... Orlando's Mickael Pietrus practiced Wednesday with a broken thumb, but didn't play Thursday night. He expects to return next week. ... The Magic are the fourth team to win 20 games. ... Nelson is averaging 22 points in his last five games.