Spurs usually go all guns blazing to begin with, especially at home.
But the Spurs then went on an 11-0 run to take command.
The Spurs then went on a 10-2 run to pull away.
The game turned when the Spurs went on a 13-4 run that began in the middle of the fourth quarter.
Spurs went to Anfield at the end of last season and beat them comfortably.
The Spurs, meanwhile, are going for their third title in seven years.
Leading by 31-29, the Spurs went on a 17-0 run to take a 48-31 lead and they never looked back.
Spurs went on to win the cup that year.
In the third, Portland increased its lead to 18 before the Spurs went on a 9-2 run.
But the Spurs went on a 14-4 run to end the half.