First they traded body blows. Then they traded compliments.

Top-seeded Michigan State fended off a scare from No. 9 Saint Louis in a grinding, defensive battle Sunday, advancing to the NCAA tournament’s round of 16 with a 65-61 victory. The Spartans will face No. 4 Louisville on Thursday in the West Region semifinals.

Coach Rick Majerus’s Billikens never led after Michigan State reclaimed the early advantage with roughly eight minutes remaining in the first half. But Saint Louis rallied late in the second half, effectively shutting down the Spartans’ path to the rim, to pare an 11-point deficit to 53-51 with 3 minutes 18 seconds left.

That set the stage for Michigan State’s Draymond Green to show the versatility that earned him Big Ten player of the year honors. With the Spartans leading 55-51, Green drove toward the basket but instead of risking a charge by plowing into a wall of Saint Louis defenders, he hurled a two-fisted overhead pass across court to sophomore guard Keith Appling.

Appling, who had been lightly covered all game, lofted a three-pointer with all the confidence he could muster and kept the faith as the ball circled slowly around the rim before falling in.

Appling finished with a game-high 19 points on 7-for-14 shooting. Green scored 16 while supplying 13 rebounds, six assists and two steals.

Afterward, Coach Tom Izzo had nothing but praise for the wiles Majerus displayed, calling him “a brilliant coach” while remaining humble about his team’s performance.

“We didn’t pretend to be God’s gift to basketball,” Izzo said of his 29-7 Spartans. “We’re a working-man’s group, and we worked hard today.”

The 64-year-old Majerus, who has made Saint Louis basketball relevant since taking over the program in 2007 after a three-year hiatus from coaching, focused his defensive scheme on Green, who delivered a triple-double in the Spartans’ round-of-64 victory over Long Island, and Michigan State’s imposing front court. He left Appling largely unmarked, gambling that the sophomore couldn’t carry the offensive load.

But Green, an exceptional floor general, used breaks in the action to remind Appling what a great shooter he was and how much confidence the team had in him.

The lead changed hands four times in the first half, and Michigan State took a 26-21 lead at the break.

It was a physical game, with big bodies hitting the floor with thuds throughout.

“We made them earn every shot they took,” said Saint Louis forward Brian Conklin (11 points), a senior who was the anchor of Majerus’s first recruiting class.

But in the end, Saint Louis simply couldn’t get enough shots to fall (hitting 35 percent from the field to Michigan State’s 54 percent), which Majerus attributed to nervousness against a more seasoned opponent.

“I think we got the tight shorts a little bit,” Majerus said, “because [Michigan State’s players] have been on this stage before. And these aren’t the nets [Izzo] wants to cut down — nor are the Elite Eight nets. He should be able to cut down the Final Four nets. And I hope they do, because they would be a great representative of the national championship and what the NCAA and the student-athlete stands for.”

By any measure, reaching the round of 32 was a success for Saint Louis (26-8). And Conklin wept with gratitude afterward, speaking about what Majerus had done for Billiken basketball and its players.

“I couldn’t imagine playing for a better coach, a better person,” Conklin said. “He doesn’t just teach you about basketball; it’s about life.”