INDIANAPOLIS -- There is a primary reason why second-ranked Michigan State will enter the NCAA tournament as one of a handful of teams that have championship components.

The No. 2 seed Spartans struggled all afternoon offensively but limited No. 18 and third-seeded Maryland to one field goal during the final 10:23 and found a way to defeat the Terrapins 64-61 on Saturday in the Big Ten tournament semifinals.

"We won the game with our defense," Michigan State's Matt Costello said. "That was the only reason we won."

Denzel Valentine, the Big Ten Player of the Year, scored 18 points, including four pressure-packed free throws during the final 21.6 seconds.

The second-seeded Spartans (28-5), who have won 12 of their last 13 games, will play 13th-ranked and fourth-seeded Purdue in Sunday's championship game.

"Maryland had a heck of a game plan against us, but the thing about us is that we don't let what is happening on offense affect our defense," Valentine said.

Valentine, who also had seven rebounds and 10 assists, made two free throws with 21.6 seconds to play for a 62-59 lead, but Maryland's Melo Trimble countered with a layup with 14.5 seconds left, cutting the margin to 62-61.

Valentine missed the front end of a one-and-one with 10.2 seconds to play, but Trimble missed a shot, Valentine rebounded with 0.8 of a second left and sank two game-clinching free throws.

Maryland (25-8) scored only four points in the final 6:54.

Trimble was 2-of-15 from the field on a day when the Terrapins shot 33.3 percent (18-of-54).

Robert Carter led Maryland with 18 points and Trimble had 11.

"In every one of our NCAA tournament runs, we haven't been involved in a lot of close games like the one today," Michigan State coach Tom Izzo said.

"We didn't play well offensively, but you win championships with defense, which is how we won today."

Costello added 10 points and five rebounds for Michigan State, which lost to Wisconsin in the 2015 Big Ten title game.

"If you like defense, that was a heck of a college basketball game," Maryland coach Mark Turgeon said, "The job we did on Bryn Forbes was terrific, but in the last three minutes, Michigan State made a couple more plays than we did."

Michigan State built a 41-33 halftime lead as Eron Harris scored eight points, with the Spartans shooting 51.7 percent from the floor (15 of 29), including 5-of-11 from 3-point range.

Valentine made only 1-of-4 shots from the field in the first half but delivered nine assists.

Maryland shot 37.9 percent from the field overall (11 of 29) but was 6-of-11 from 3-point range.

Carter had 13 points before intermission, including 3-of-4 from beyond the arc. Rasheed Sulaimon had eight points, including two 3-pointers.

"What happened to us offensively in the last 10 minutes is unfortunate, but at no point did we let that affect us," Sulaimon said. "We made one field goal in the final 10 minutes and were one possession for winning against one of the best teams in the country."

Michigan State led 36-24 with 3:59 left in the half, but two of Carter's 3-pointers helped the Terrapins get to within single digits through 20 minutes.

NOTES: Maryland advanced to the semifinals with a 97-86 victory over No. 11 seed Nebraska, getting 26 points from Jake Layman and 23 from Diamond Stone. ... The Terrapins are the only Big Ten team with five players averaging in double figures, and those five each reached double figures against the Cornhuskers. ... Maryland is 5-1 in neutral site games. ... Michigan State advanced to the semifinals with an 81-54 victory over No. 7 seed Ohio State, getting 19 points from Denzel Valentine. ... The Spartans beat Maryland 62-58 in last year's Big Ten Tournament semifinals and defeated the Terrapins 74-65 in their only regular-season meeting in 2016.