ANN ARBOR, Mich. — On No. 15 Michigan’s final drive of the first half Saturday — a 12-play, 64-yard series that lasted over five minutes and ended with a touchdown — the Wolverines faced four third-down plays.

Entering its toughest matchup of the season, the Maryland football defense had shown marked improvement from last year’s squad, including holding opponents to a conference-low 29 percent conversion rate on third downs.

But time and again at the Big House, the Wolverines moved the chains. One after another, third-and-short was followed by first-and-10. And as Michigan quarterback Shea Patterson rolled to his left on Michigan’s final play of the first half, he fired across the middle to wide receiver Ronnie Bell, who slipped past two converging Maryland defenders and stumbled his way into the endzone, establishing a two-score lead in a game the Terps once miraculously led.

Maryland’s offense failed to execute much of anything before managing two late scores to narrow the deficit to 42-21 against the nation’s top-ranked defense. That put the Terps’ defense on the field for over 35 minutes to contend against Patterson, who picked apart the Terps’ secondary and left players with hands on their hips, left out to dry by a boom-or-bust offense that rarely boomed.

“Our defense had to play a lot of snaps in the first half,” interim head coach Matt Canada said. “What was it, 10-7 there? And they got the last one in, the last drive there. Our guys were just worn down.”

At one point in the first quarter, the offense’s three-and-out meant its defense had only about a minute-and-a-half of game time between drives, and the Wolverines marched down to convert a field goal on the next series.

Then, running back Ty Johnson ran 98 yards down the sideline on the ensuing kickoff, handing Maryland a 7-3 lead but forcing the defense straight back on the field. Safety Darnell Savage intercepted a tipped pass two plays into that series, but the Terps couldn’t manage a first down and punted, leading to two back-breaking drives from Michigan that tipped the game out of balance.

Maryland ran eight offensive plays in the second quarter compared to Michigan’s 23, as Patterson used his legs and his arm to poke holes in Maryland’s defense.

The Terps finished with a season-low 50 offensive plays, making it three consecutive games with limited possession. Maryland ran 52 plays in its abysmal loss to Temple, and its explosiveness held it to 51 plays against Minnesota.

“52, 51 and 50. It’s unbelievable. The first factor is the special teams scored again. We’ve had three games in a row we’ve had a special teams score or a defensive score,” Canada said. “We’ve got to stay on the field on offense, whether you score fast. Last week we scored fast. Last week it was no problem having 51 plays because we scored a lot of points. This week we didn’t.”

Michigan keyed in on Maryland’s run game and the team’s aerial ability couldn’t pose much of a threat. Quarterback Kasim Hill attempted four throws in the first half, while the Terps had 17 plays altogether. Johnson and fellow running back Anthony McFarland combined for 37 yards. Hill finished with 62 yards through the air.

“Today just wasn’t our day,” said running back Tayon Fleet-Davis, who finished with 63 yards. “We kind of hurt ourselves.”

So as Maryland’s offense stumbled against a standout defense that was without two of its premier defensive lineman, the Terps’ defenders were left exposed once more, playing for over 30 minutes for the third straight game.

“It’s pretty tough,” defensive back Antoine Brooks said. “You have a lot of responsibility to play football. You’ve just got to play football. You’ve got to keep playing. It doesn’t matter what happens. Football is football so anything can happen playing football.”