The Spurs won 110-95 in the opener, a game that will be best remembered for an air conditioning failure that made temperatures soar to nearly 90 degrees in the second half. LeBron James cramped up in the heat and left with about 4 minutes remaining.
The teams spent their two off days practicing at the Spurs' training facility while the AT&T Center was being used for other events. They will be back in the arena, where the Spurs have won an NBA-record eight straight playoff games by 15 or more points, for Game 2.
Here are five things to watch Sunday night:
HEAT'S HEALTH: James had two days of treatment after he couldn't make it to the finish of Game 1 because of cramps. He practiced Saturday and has said he expects to be 100 percent for Sunday night.
He's had cramping problems before, missing part of Game 4 of the 2012 NBA Finals, so his condition will have to be monitored. But James doesn't sound too concerned.
"I'm doing well, doing a lot better. The soreness is starting to get out," he said. "I'm feeling better than I did yesterday and with another day, I should feel much better tomorrow."
WEATHER REPORT: It's expected to be much cooler inside the AT&T Center on Sunday.
The breaker that failed Thursday night, which NBA Commissioner Adam Silver said was about the size of a car battery, was repaired by Friday afternoon. San Antonio's WNBA team played a home game Saturday night without issues, and the Heat are expecting a much different climate than they faced in Game 1.
"We anticipate we will play in a very cool gym. We will have to deal with that now," coach Erik Spoelstra said. "I don't know if guys will be wearing tights under their shorts and long-sleeved shirts. I don't know."
KEEP IT CLEAN: The Spurs committed 23 turnovers that led to 28 Miami points in the opener. The Heat were almost as sloppy, turning it over 18 times for 27 points.
"My guess is you won't see that tomorrow night, turnover-wise," Spurs coach Gregg Popovich said Saturday. "I don't think either one of us will turn it over as much as we did. In that regard, we were both pretty sloppy."
SEND SUBS?: Dwyane Wade and James have both said the Heat may have benefited from a deeper rotation in Game 1.
Spoelstra used only four reserves in the hot conditions, and James said Saturday he could've seen where Udonis Haslem, or James Jones or Toney Douglas could have gotten a few minutes to keep the starters fresher for the finish.
"Spo is going to coach the game the way he sees the game going and flowing, and we're definitely going to ride with that, the way he calls the game," James said. "And like I said, Thursday's game was extreme measures. And I don't expect that tomorrow night, but we'll see."
MEN IN THE MIDDLE: Spurs big men Tim Duncan and Tiago Splitter combined to make 14 of 16 shots in Game 1, with Duncan scoring 21 points and Splitter adding 14. San Antonio outscored Miami 48-36 in the paint.
The Heat have been employing a small starting lineup with Chris Bosh at center and Rashard Lewis as an undersized power forward, and will have to find a way to contain the Spurs' bigs.
"We need to do what we do better and harder," Spoelstra said. "They make it tough with their passing and, you know, getting into the paint with their roles and spreading you out with 3-point shooters. So we need to do that better, there is no question about it. Those were big-time relief points."