After Kristina Santiago’s scorching first half at Mott Gym on Tuesday night, there was only one way the Cal Poly women’s basketball team was going to lose to visiting Cal State Fullerton.

The Mustangs would have to beat themselves.

And now the rest of the Big West Conference Tournament is shaping up that way, too.

The recently named two-time Big West Player of the Year, Santiago scored 20 of her 31 points in the first half, and despite seeing a 24-point lead whittled to 10 late in the second half, Cal Poly (17-13) pulled away for a 71-53 victory over the Titans (11-19) in the first round of the conference tournament.

With the No. 2, 3 and 4 seeds all succumbing to upsets in other first-round games around the conference, things are lining up nicely for the Righetti High grad to help the Mustangs take the tournament title and make their first-ever NCAA Tournament appearance.

“Whenever she gets the ball, it’s automatic. Kristina Santiago is an amazing player,” Cal Poly redshirt freshman point guard Ariana Elegado said. “It’s amazing when she’s on fire.”

Santiago shot 13 of 16 from the floor, good for 81.3 percent. She nearly outscored Cal State Fullerton on her own in the first half as the Mustangs went to the break with a 41-23 lead.

The only problem for Cal Poly came when Santiago stopped scoring consistently and the offense failed to fill in from elsewhere.

After pushing the lead to 55-31 with 11:27 left, the Mustangs committed six of their 19 turnovers during a 14-0 run by Cal State Fullerton.

Santiago went more than 10 minutes in the second half without taking a shot, and the Titans cut the deficit to 55-45 with 6:05 left.

“My concern mostly was we can’t be doing that against teams when it’s a closer game,” said Santiago, who became Cal Poly’s all-time scoring and rebounding leader before the end of the regular season. “I know our huge lead kind of saved us a little bit. If the game were closer, who knows what would have happened?”

Starters Caroline Reeves, Ashlee Burns and Kayla Griffin combined to go scoreless in the game. The Mustangs were unprepared to have the usually reliable scorers be shut out, but Elegado had 14 points off the bench, and Christine Martin subbed in to score 12, including 3 of 5 from 3-point range.

It was Elegado’s three-point play on a driving left-handed layup with 4:52 left that seemed to refocus Cal Poly.

The Mustangs finished the game on a 14-6 run and head into the semifinal round of the tournament against Long Beach State at the Honda Center in Anaheim at noon on Friday with plenty of momentum.

“After that and-one, we just got together and when we came together as a team,” Elegado said. “We thought this is the turning point.” Cal Poly frustrated Cal State Fullerton standout Megan Richardson for most of the night.

The Big West’s second-leading scorer behind Santiago at 16.2 points per game coming in, Richardson started 0 for 8 from the field and 0 for 5 from 3-point range.

She needed only six points to move from fifth to second on the Titans’ all-time scoring list but didn’t make her first shot from the field until a 3-pointer with 8:30 left.

Richardson rebounded to finish with a team-high 13 points on 4 of 15 from the field, but she was the only Cal State Fullerton player to score more than nine.

It continued a trend of off games for Richardson against Cal Poly. She scored 10 points in a loss to the Mustangs in Fullerton and only two points in her last trip to Mott Gym.

“I hope it’s our defense,” said Cal Poly coach Faith Mimnaugh, who recruited Richardson out of high school, “because she’s a heck of player. We just know if we give her open shots, she’s sure to make them. We didn’t come off Richardson.”