EAST LANSING, Mich. — Michigan State is 6-0 in the Big Ten, its best start to conference play in coach Tom Izzo’s 15 seasons.

But Izzo is thoroughly unimpressed, especially after Wednesday night’s lackluster 70-63 victory over Iowa. The sixth-ranked Spartans lacked intensity and let the overmatched Hawkeyes cut a 19-point lead to three late in the game.

“I’m used to our great teams playing with incredible emotion,” Izzo said. “This team is not quite like that right now. … I’m not happy with tonight’s performance. I’m not happy with where we are.”

Raymar Morgan scored 16 points to pace Michigan State (16-3, 6-0), which led by 19 midway through the second half before Iowa got back into it. Matt Gatens hit a 3-pointer with 2:05 left to cut the deficit to 64-61, but the Hawkeyes (7-12, 1-5) couldn’t get any closer.

The last Spartans team to open 7-0 in league play was the 1977-78 squad led by Magic Johnson.

Durrell Summers had 12 points for Michigan State and Kalin Lucas added 11. The Spartans have won seven straight since losing to Texas on Dec. 22.

Gatens scored 17 points for Iowa. Aaron Fuller had 13 points and nine rebounds.

Every other team in the Big Ten already has at least two losses this season. But the quest for the conference title is about to get tougher for Michigan State. Six of the Spartans’ next eight games are on the road, starting with trips to Minnesota and Michigan.

“I’m starting to get concerned,” said Michigan State’s Draymond Green, who had 11 rebounds and nine points. “We play six of our next eight on the road. … If we play like that, we’re going to lose.”

Iowa had beaten Tennessee State and Penn State since losing to Michigan State 71-53 in Iowa City on Jan. 9. But the young Hawkeyes, with only two upperclassmen on their active roster, could not come all the way back in this one.

Iowa coach Todd Lickliter called it a “letup” by Michigan State.

“They were in control,” Lickliter said. “To our guys’ credit, they continued to fight. … These are opportunities. It’s well documented that we’re young and we’re trying to build something.”

Michigan State was lethargic early, particularly on defense. Iowa jumped out to a 19-14 lead midway through the first half, making eight of its first 13 shots from the floor.

The Spartans scored the next 15 points, capped by Lucas’ 3-pointer and Morgan’s dunk, to take a 29-19 lead with 6:30 left in the half.

The 5-minute scoreless streak cost the Hawkeyes, who trailed 35-23 at halftime.

Michigan State led 55-36 midway through the second half. But the patient, determined Hawkeyes wouldn’t fold.

The 3-pointer by Gatens cut the lead to three. Korie Lucious scored on a driving layup to put Michigan State ahead 66-61 with 1:33 left.

The Hawkeyes cut the lead to three again with 17 seconds left on two free throws from Jarryd Cole, but never got a chance to tie it. Lucas and Green made free throws down the stretch to seal the victory.

“It was nice to see that we could come back a little bit in a great environment,” Gatens said. “But we can’t be satisfied.”