ANGELES, May 22 (AFP) - Tim Duncan was the lone tower but he had plenty of help from the "Twin Tinies." Duncan collected 37 points and 14 rebounds and Jaren Jackson and Avery Johnson had huge fourth quarters as the San Antonio Spurs pushed the Los Angeles Lakers to the brink of elimination with a 103-91 victory in Game Three of their National Basketball Association Western Conference semi-final series. Even with fellow "Twin Tower" David Robinson limited to 24 minutes by foul trouble, Duncan simply was unstoppable. He was 19-of-23 from the line as he matched the 1999 individual playoff high. In the first three quarters, Duncan carried the offense. In the final period, he effectively passed out of double-teams to the perimeter, where Jackson and Johnson were burying open jumpers. The 6-foot-4-inch Jackson scored a playoff career-high 22 points off the bench, making 9-of-15 shots. He scored 13 points in the fourth quarter and helped hold Kobe Bryant scoreless for the final six-plus minutes. Johnson was held to two points through the first 3 1/2 quarters but made three clutch jumpers in the final six minutes. He is shooting 55 percent from the field in the postseason. The Spurs scored the last 13 points as they again outplayed the Lakers down the stretch. They remained unbeaten on the road in the postseason and can advance to the conference finals for the fifth time in franchise history with a win Sunday. The Lakers did not score in the final 1:55, missing five shots and two free throws. Superstar center Shaquille O'Neal had 22 points and 15 rebounds but did not have a basket in the final nine-plus minutes. bb99 --=-=-- 