HOUSTON — LaMarcus Aldridge scored at will in the paint before the San Antonio Spurs turned a late barrage of 3-pointers into a 103-92 victory over the Houston Rockets in Game 3 of the Western Conference semifinal series on Friday night at Toyota Center.Aldridge, who scored four points in the Rockets’ blowout win in Game 1, had 26 points on 12-of-20 shooting from the field. Kawhi Leonard added 26 points, 10 rebounds and seven assists as the Spurs took a 2-1 series lead.Game 4 is set for Sunday.After a dunk by Rockets forward Trevor Ariza that cut the deficit to 76-72 with 7:50 left, Aldridge and Leonard combined to score the next 12 points for the Spurs. The last Leonard basket was a 3-pointer, and when Danny Green followed with two 3s, the San Antonio lead was 94-82 with 3:15 left.Rockets guard James Harden scored a game-high 43 points but had just five assists. Ariza totaled 17 points but had two after the intermission.The Rockets’ three-man bench of Eric Gordon, Nene and Lou Williams combined for 10 points on 3-of-19 shooting. Houston shot just 36.4 percent from the field and failed to rattle San Antonio, which was playing without injured point guard Tony Parker.It was clear from the start that the Spurs were going to defend with increased vigor despite the loss of Parker. The Rockets scratched together just six field goals on 25 percent shooting in the first quarter. While the Spurs weren’t much better (34.6 percent), they did manage two transition baskets and 12 points in the paint. Yet the Rockets led 21-19 entering the second quarter.When Houston aided San Antonio with seven second-quarter turnovers, the Spurs took advantage. After starting 1 of 7 from the floor in the quarter, Leonard converted a dunk with 3:37 left before adding a baseline turnaround jumper, a second-chance basket and two free throws to lift the Spurs to a 43-39 lead.NOTES: With G Tony Parker sidelined for the remainder of the postseason (ruptured quadriceps tendon), rookie G Dejounte Murray started in his place. Murray, who started eight games during the regular season, logged just 13 minutes in Games 1-2. Veteran G Patty Mills maintained his role off the bench. … The Rockets tweaked their rotation a bit, with G James Harden taking his first rest with 2:20 left in the first quarter. Harden normally plays the entire opening quarter before resting to start the second. … Spurs C Pau Gasol scored 12 points and became the sixth player in NBA history with 2,000 points, 300 assists and 200 blocks in the postseason (Kareem Abdul-Jabbar, Shaquille O’Neal, Tim Duncan, Hakeem Olajuwon, Patrick Ewing).