BOSTON — They announced a crowd of 41,632 at Boston College’s Alumni Stadium on Saturday night.

When the game ended, it seemed all of them were on the field.

Their Eagles, who came in as 17-point underdogs, had just upset No. 9 USC, and there was reason for the home fans to celebrate.

“It’s a great night for our team, for the players. They played really hard,” coach Steve Addazio said after the 37-31 victory. “They had a rough week last week (a loss to Pittsburgh). They had a hard week of practice. There’s a lot of people second-guessing them, but they had a real steel resolve.

“This was a great win. There (were) big plays made by a lot of people.”

This is supposed to be a rebuilding year at BC. The Eagles — who reached a bowl game last season, Addazio’s first — were hit with serious losses. Gone are all-time leading rusher Andre Williams; all-time leading receiver Alex Amidon; kicker Nate Freese, No. 1 in scoring; and quarterback Chase Rettig.

This season was supposed to be painful, but BC is 2-1 with FCS Maine coming next Saturday.

With the game dedicated to the late Welles Crowther, a former BC lacrosse player who saved lives before losing his at the World Trade Center on Sept. 11, 2001, the Eagles played inspired football from start to finish. They later gave a game ball to his family.

Graduate senior quarterback Tyler Murphy, a transfer from Florida, ran for 191 yards, including a 66-yard touchdown late, and passed for 54 yards. The Eagles rushed for 452 yards and five TDs in their first win over a ranked team since 2008.

“It meant a lot, especially after last week’s loss,” Murphy said. “It was a tough loss for us, and Coach really challenged us as a team this week. We really went after it.

“It just goes to show that if we really set our minds to something and we play as a team, sky’s the limit.”

BC had dropped 12 straight to teams in the Top 25. It was also the program’s first win over a Top 10 team since 2004.

The Eagles, totaling 506 yards, ran up the huge ground numbers against a USC team that had allowed 285 rushing yards in its first two games, both wins. The rushing total was the second highest in BC history.

Freshman running back Jon Hilliman ran for his first two college touchdowns, rookie wide receiver Sherman Alston took a reverse 54 yards for his first a score and sophomore running back Tyler Rouse also scored.

“They outplayed us,” said Steve Sarkisian, who suffered his first loss in three games at his new job. “They beat us in all three phases.

“They controlled the line of scrimmage on both sides of the ball. The end result was we didn’t get it done. It starts with me coaching and goes to everyone in that locker room. We need to improve.”

Despite the nonconference loss, Sarkisian said, “The goal obviously of being Pac-12 champs is very alive for us.”

The Eagles spotted their visitors leads of 10-0 and 17-6 and then roared back — dominating on both sides of the ball and special teams.

Boston College scored 24 straight points before USC quarterback Cody Kessler went 8 of 9 through the air and took his team to a touchdown with 3:43 remaining.

Murphy then pulled off his long run, but Kessler came right back, throwing his fourth touchdown pass with 1:18 left.

USC then tried an onside kick that was recovered by Boston College wide receiver Shakim Phillips.

Hilliman, who totaled 89 yards on 19 carries, ran for 22 yards on the first play and 17 more on two more carries — and the Eagles were able to run out the clock before their fans stormed the field.

The Eagles sacked Kessler five times, with linebacker Josh Keyes making 5 1/2 tackles for loss in the win that lifted BC to 2-1.

One of Kessler’s TD passes was a 51-yard swing pass to running back Javarious Allen.

Andre Heidari kicked a 52-yard field goal for USC and Joey Launceford hit a 25-yarder for Boston College.

Kessler, who dissected Boston College last year’ in USC’s 35-7 win in Los Angeles, finished 31 of 41 for 317 yards. Allen, the No. 2 rusher in the Pac-12 with 100-yard games in the first two, netted just 31 yards and his team just 20 in the loss.

NOTES: Boston College players all wore something red, including shoes, in honor of the late Welles Crowther, the former Boston College lacrosse player who saved at least 12 people in New York on Sept. 11, 2001, at the cost of his own life. People described Crowther as “The Red Bandana Man” and the red bandana was the theme of the night. … USC hosts Oregon State in a Pac-12 game next Saturday, and Boston College is home for FCS foe Maine in the third of four straight home games. … Former Boston College baseball player Pete Frates, whose battle with ALS led to him being the catalyst for the Ice Bucket Challenge, was honored with a video tribute at halftime.