McGrady scored 10 of his 23 points in the fourth quarter and Scola had 18 points and a career-high 18 rebounds in the Rockets' 97-86 victory Wednesday night.
"The fourth quarter, usually the best player has got to step up and lead the team," McGrady said. "I just couldn't afford for us to lose this game, so I had to impose my will on it."
McGrady also had 11 rebounds and nine assists to help the Rockets keep pace in the tight Western Conference race.
McGrady, wearing a bandage on his left shoulder after spraining it late in Monday night's win over Sacramento, was 4-for-15 from the field after three quarters. He made three straight jumpers in a two-minute span in the last quarter as the Rockets opened a double-digit lead and finally put away the Timberwolves.
"I got a little rhythm going," McGrady said, "and I took over the ballgame."
The Rockets outrebounded the Wolves 58-38 and scored 14 second-chance points to win for the 19th time in their last 21 home games.
Al Jefferson had 21 and 10 rebounds for Minnesota, which had won four of its last six games.
"They beat us pretty good on the boards," Wolves coach Randy Wittman said. "Our defense wasn't bad, but we gave up too many second-chance baskets."
The Rockets looked sluggish most of the night, going 4-of-19 from 3-point range, committing 14 turnovers and never leading by more than 12. Scola seemed like the most active Rocket on the floor, fighting for boards and scrambling for every loose ball.
"We weren't playing very good," said Scola, an NBA rookie from Argentina. "Every possession, everything counts. You're not playing very good, you're not getting easy baskets, you need to play hard. It creates more possessions for you and it gives you more chances to score."
The Rockets open a five-game road trip against San Antonio on Sunday. The teams had identical records (49-23) after wins on Wednesday and both were one game behind New Orleans in the race for the No. 1 seed in the West.
"Every game is important," Scola said. "You win one game, you go up to the 2-spot. You lose one game, you go down to seven. That's the way it is and that's the way it's going to be from now on, until the regular season is over. We've got to be ready for that and we've got to know that's the way it is."
Kirk Snyder, acquired from Houston in a trade on Feb. 21, had seven points and four assists in the first quarter to keep the Wolves close. He finished a fast break with a dunk, but Rafer Alston sank a 3-pointer in the final seconds of the quarter to give Houston a 24-23 lead.
The Rockets built an eight-point lead in the second quarter, but the Timberwolves stayed close behind Jefferson and Ryan Gomes, who scored 10 points apiece in the first half. Gomes finished with 17.
McGrady aggravated his shoulder injury on a drive into Marko Jaric just before halftime. He winced as he walked to the free-throw line but hit both shots to put the Rockets up 46-40.
Houston rebuilt its eight-point lead early in the third quarter. Gomes made a 3-pointer and Jefferson dunked over Dikembe Mutombo to cut it to 53-50.
Scola had a putback and converted a three-point play to push the lead back to eight. He had a steal later in the quarter that led to an easy layup for Alston.
"It took us until the second half to really find our defensive energy that was needed to win the game," Alston said. "We got an all-around night from Tracy and Scola."
The Rockets outrebounded Minnesota 46-31 through three quarters and led 69-60.
The Wolves opened the final quarter with a 12-5 run, spurred by three straight baskets by Rashad McCants. Bobby Jackson and McGrady answered with consecutive baskets to push the lead to 78-72. Jackson tipped in McGrady's miss to put Houston up by 12 with 4:15 left.
The Rockets have won 29 of their last 33 games.
At halftime, the Rockets honored Mutombo with a video tribute. Team owner Les Alexander presented Mutombo with a $500,000 check for the hospital that Mutombo built in the Democratic Republic of Congo. NBA commissioner David Stern was on hand for the ceremony. Yao Ming, on crutches after breaking a bone in his left foot in late February, also attended. ... Former president George H.W. Bush had a courtside seat next to Houston Astros owner Drayton McLane. ... Snyder had 12 points and six assists for Minnesota. ... McCants scored 16 points.