Pitino's 24th-ranked Louisville Cardinals shot only 36.1 percent from the field - leading scorer Mike Marra was 1-for-10 - and led undermanned San Francisco by one at halftime.
But they persevered due to their defense.
Louisville outscored the Dons 36-11 in the second half on its way to a 61-35 victory in front of 21,049 at the KFC Yum! Center.
Four players scored in double figures, led by Peyton Siva and Terrence Jennings with 14 points apiece, for the unbeaten Cardinals (7-0). Both were 5 for 8 from the field, while their teammates were a combined 12-for-45 (26.7 percent).
"Coach said, ‘Sometimes the shots don't go in,'" said Jennings, the 6-foot-10 junior center who also grabbed nine rebounds in only 19 minutes. "We knew we had to keep playing defense, keep getting stops...Sometimes there's a lid on the rim, you have to expect that and try to get stops as much as possible."
Sparked by Siva and its defense Louisville outscored San Francisco 16-0 early in the second half and held the Dons (3-5), who had only eight players in uniform after losing starting point guard Cody Doolin to an eye injury in the first five minutes, to only five second-half field goals. Siva, the sophomore point guard, hit a pair of three-pointers and assisted an inside basket during the Cardinals' quick start to the second half.
"What I told them at halftime is there is always a tournament game when shots aren't falling and you are going to have to win it with defense," Pitino said. "And they did it in the second half, they won it with defense. Peyton Siva gave us a big run off his defense and were able to extend the lead."
Louisville scored the first nine points of the game, as San Francisco turned the ball over on its first three possessions. Siva accounted for seven of his team's first nine points with an assist, a three-pointer and a dunk off a steal. He also finished with five assists and four steals.
The depleted Dons went without a field goal for the first 4:29. However San Francisco scrapped its way back in the game.
Trailing 20-8 at the 10-minute mark the Dons went to their spread offense and outscored Louisville 16-5 over the remainder of the first half. Michael Williams' three-pointer with 1:02 left tied the score at 24 before Siva hit one free throw with 4.9 seconds remaining to give Louisville a one-point lead at intermission, 25-24.
San Francisco shot 40.9 percent (9 for 22) in the first 20 minutes against a team that had limited its first six foes to 31.8 shooting in first halves. The Cardinals, meanwhile, shot 37 percent (10 for 27) in the first half and made only 4 of their 17 three-point tries (23.5 percent).
"I just think our guys were so consumed with our shots not falling that they were forgetting that we made seven mishaps defensively, not switching at the right time, not guarding the post the right way," Pitino said. "All because we were taken out, because this is a young team, an inexperienced team...because inexperience isn't an excuse anymore...an inexperienced team that didn't realize defense wins. So we broke down defensively and they shot, in the first half, one of the highest percents against us this season. So we made adjustments, so let's start thinking defense and not offense."
The two teams traded baskets to start the second half before the Cardinals ran off 16 in a row. Siva started the spurt with a three, then Jennings scored inside before Siva hit another three. Chris Smith hit a three, then Gorgui Dieng hit a layup off a feed from Siva. Jennings' old-fashioned three-point play capped the run that came via some good, old-fashioned defense.
"The second half we just decided we were going to turn it up on D and rely on our D to get this win," said sophomore forward Rakeem Buckles, who grabbed a game-high 10 rebounds.
Smith added 11 and Preston Knowles 10 for Louisville, which committed a season-low five turnovers while forcing 16 to outscore San Francisco 21-0 in points off turnovers.
Williams led the Dons with 14 points.
Marra, who came in averaging 13 points per game, finished with three in 22 minutes.
Louisville shot 35.3 percent (12 for 34) in the second half, hitting 6 for 19 (31.6 percent) from three-point range. San Francisco was 0-for-8 from long range, and was outrebounded 30-16, in the second half.
"We couldn't get a whole lot going in the second half," said San Francisco coach Rex Walters, a former standout at Kansas in the early 1990s. "They're pretty darn good. We spent so much energy on the defensive end, and you get nothing easy...Tired legs equal bad shots. I told our guys, ‘You couldn't have a worse situation - a Top 25 team, athletic, playing at a great arena, sometimes you feel like you're out there playing five-on-eight."
Louisville hosts No. 20 UNLV on Saturday.
"Of all the teams I have seen this year, none is better than UNLV," Pitino said. "That is not hyping them up, they just went to Southern Illinois from across the country and beat them by 31...and team that was 5-2, pretty impressive. So we have our work cut out for us, and we will be ready."