CHICAGO -- Michigan State showed up in the nick of time Friday.
Plagued by lackluster shooting, turnovers and poor decisions for nearly 30 minutes, the Big Ten's defending tournament champs abruptly shifted fortunes, rallying from a 13-point deficit to claim a 59-56 victory over Iowa in the conference quarterfinals at the United Center.
"These guys took over, and every one of them made a heroes' play at the end," Spartans coach Tom Izzo said of his players. "We found a way to luckily, luckily win."
Michigan State guard Gary Harris calmly hit two free throws with 29 seconds left to pad the lead after the Hawkeyes closed to within a point in the final minute.
Iowa's Roy Devyn Marble missed a last-ditch 3-point attempt with five seconds left in regulation.
Michigan State meets Ohio State in Saturday's semifinals. The Buckeyes advanced with a 71-50 quarterfinal victory over Nebraska.
Adreian Payne collected 18 points and 10 rebounds, while Keith Appling and Harris each added 13 for the eighth-ranked and third-seeded Spartans (25-7). Mike Gesell topped sixth-seeded Iowa (21-12) with nine points.
"We felt we deserved to win that game," Iowa forward Melsahn Basabe said. "A couple things went their way, a couple things that didn't go our way. Then we made a little run at the end.
"We competed hard, unfortunately we just weren't able to get that win."
Harris' 3-pointer with 4:10 to play capped a mammoth momentum swing and gave the Spartans their first lead of the game at 50-49.
By the 1:54 mark, Michigan State appeared in control with a 57-51 lead. However, Iowa's Aaron White hit a 3-pointer, and Basabe turned a Spartans turnover into a bucket in the paint, and the Hawkeyes suddenly closed the gap to 57-56.
Iowa led by as many as 13 points early in the second half, but Michigan State began to chip away when Payne dunked 77 seconds into the half and then added a baseline 3-pointer a minute later as the Spartans closed within 33-26.
Payne's successful 3-pointer was Michigan State's first after eight misses.
"We just had to focus in," Appling said. "We knew we were making too many mistakes, and we had to get this team to start picking up our play."
The Spartans briefly crept to within six at 35-29 on Appling's dunk, but the Hawkeyes pushed the lead back to 12. Zach McCabe's 3-pointer made it 45-33 with 12:15 showing.
Iowa's last double-digit lead came with 10:24 to go when McCabe's layup made it 47-35.
"We didn't show up for the first half, and that falls on me," Izzo said. "In general, Iowa outplayed us three-quarters of that game and deserved to be in the position they were in."
Appling's jumper 14 seconds later launched another Spartans comeback. This time, energized Michigan State outscored Iowa 15-2 over the next 6:14 to claim its first advantage.
The Hawkeyes never trailed in the opening half, sprinting to a 5-0 lead before the Spartans hit their first field goal at the 16:41 mark.
Iowa held a 22-14 lead late in the half, due in part to 8-for-9 free-throw shooting and 3-pointers from Josh Oglesby and Marble.
Iowa pushed the advantage to 30-20 by halftime. Michigan State had missed all eight 3-point tries and was 8-for-30 (26.7 percent) from the field in the half. Marble scored a game-high nine points for the Spartans before the break. Iowa was 10-for-20, with six points from Gesell.
The Spartans are destined for the NCAA tournament even if they don't make the Big Ten final. Iowa feels it deserves to continue its season, too.
"We're going to be playing in one of the postseason tournaments, the NCAA or the NIT," Gesell said. "We'll find that out soon, and we'll get ready for that."
NOTES: Saturday's semifinals will be televised by CBS Sports. All tournament games are sold out. ... This is the third straight year Iowa and Michigan State have met in Big Ten tournament. The Spartans eliminated the Hawkeyes in the first round in 2012 and in quarterfinals in 2011. ... Michigan State also took the only regular meeting with a 62-59 decision in Iowa City on Jan. 10. ... The Spartans have won 11 of the teams' past 12 meetings. ... Basabe became the second player in tournament history to collect 10-plus points, 10-plus rebounds and five-plus blocks in a game when he had 10 pointers, 12 boards and five blocks in Thursday's victory over Northwestern ... Iowa is 15-13 all-time in Big Ten tourney play, and it won the 2001 title. Michigan State is 19-12 with championships in 1999, 2000 and 2012. ... Izzo calls March his favorite month, and with good reason. He's 77-35 overall in the month and 24-8 since 2009. ... The Hawkeyes' 73-59 win over Northwestern on Thursday was third-year coach Frank McCaffery's 50th at Iowa. He won his 300th career game on March 9 against Nebraska.