So he got all of his points the old-fashioned way — at the free-throw line — and he earned every one of them.
That was emblematic of the Cougars' night, as they shot a school-record 53 free throw attempts, making 38. Hartsock was 12-of-12 from the charity stripe and 0-for-6 from the field.
In the end, BYU pulled away late and recorded a 79-60 grind-it-out victory over Portland before a crowd of 4,159 at the Chiles Center, including a large and loud contingent of Cougar fans.
"This was a game where we had to dig deep and find a way to win," said coach Dave Rose. "That's the way we had to play to get this done."
BYU improved to 20-6 overall and 8-3 in the West Coast Conference. Portland fell to 6-18 and 3-8.
The Cougars have now won at least 20 games for seven consecutive seasons, all under Rose, which is also a school record.
BYU also set a school record with 18 steals, including eight by forward Brandon Davies, to go along with his team-high 18 points and 13 rebounds.
The Cougars trailed by four, 39-35, early in the second half, when they started to pound the ball inside to Davies and Hartsock.
"They just battled," Davies said of the Pilots. "You've got to give them credit. They had us on our heels for a while."
During one four-minute stretch, Hartsock went to the free-throw line 10 times and hit all 10 attempts to put BYU up by six, 49-43.
"We knew it would be a physical game," Davies said. "We were fortunate enough to get those calls."
In the second half, the Cougars scored 29 points from the free-throw line and 18 points from the field.
Meanwhile, BYU's 3-point shooting woes continued, as the Cougars went 3-of-16 from behind the arc. Cusick hit two of those in the first half, giving BYU a lift.
The Cougars are now 17-of-101 from 3-point range in their last six games.
Hartsock, BYU's leading scorer, who has scored in double figures in 26 of their 27 games this season and is referred to as "Old Reliable" by his teammates, was scoreless in the first half after playing only four minutes due to foul trouble.
"We challenged him pretty good at halftime," Rose said of Hartsock. "He's a guy that we look to. (Portland) was really physical with him. He had some good looks at the basket that didn't go down."
BYU led by five, 32-27, at halftime, but Kevin Bailey scored eight straight Pilot points to open the second half to give Portland a 35-34 advantage. The Pilots went up by as many as four.
That's when Davies and Hartsock started to take over. Thanks to Hartsock's success at the free-throw line midway through the second half, the Cougars seized a 49-43 advantage. BYU pushed that lead to 10 to cap a 22-8 run, and then held on from there.
The Cougars shot 35 percent for the game, but with 53 trips to the free-throw line, it didn't matter much. Meanwhile, Portland was a miserable 10-of-23 from the free-throw line.
BYU hosts Pepperdine next Saturday (4 p.m., MST, BYUtv).