Michigan State QB Jeff Smoker evades Marshall defensive end Ralph Street. Smoker was 16-of-24 for 138 yards.(AP)

"If you let Duckett get into the secondary, you have huge problems," Marshall coach Bob Pruett said. "If you keep him in traffic, he's manageable. But if gets into the open, he's a load."

Duckett did most of his damage in the second half, with 16 carries for 185 yards and a touchdown. He put Michigan State ahead 27-17 with a 36-yard touchdown run with 4:44 left in the game. His 64-yard run to begin the final quarter set up a field goal that gave the Spartans a 20-10 lead.

He could feel the benefits of eliminating the cheeseburgers and late-night pizzas from his diet.

"I had great stamina and I got stronger as the game went on" Duckett said. "I worked hard and lost the weight just in case of situations like this."

Jeff Smoker was another Spartan ready to perform for Michigan State.

The freshman with All-American credentials from Manheim, Pa., became the Spartans' starting quarterback on the first possession of the second quarter after Ryan Van Dyke left the game with a bruised right thumb. Van Dyke is expected to be ready to play at Missouri next week.

Smoker completed 16 of 24 passes for 138 yards with a touchdown and an interception.

"When I looked into his eyes before that first play, I could tell he was a little nervous," said Chris Baker, who caught eight passes for 93 yards and a touchdown. "I just said, 'Smoke, just relax.' Once he got the butterflies out of the way, he was all right."

Smoker wasn't the only inexperienced quarterback on the field.

Marshall sophomore Byron Leftwich, making his second start, had three touchdown passes and three interceptions -- one in the Spartans' end zone and one at their 1-yard line. Leftwich completed 27 of 44 passes for 227 yards.

"I think he did a lot of good things, but he really hurt us in the red zone," Pruett said. "But this was his first big-time game."

Nathan Poole, who caught eight passes for 76 yards and a touchdown, was Leftwich's favorite target. Brandon Carey turned a draw into a 37-yard gain on the third play of the game, but finished with just 48 yards on eight carries.

Marshall entered the game with the nation's longest winning streak, which began after losing to Bowling Green on Oct. 31, 1998.

Cedric Henry made two interceptions to lead the Spartans defensively.

Van Dyke found Chris Baker wide open on the sideline for a 37-yard touchdown play midway through the first quarter to give the Spartans a 7-0 lead.

Marshall tied it when Leftwich threw an 11-yard pass to Poole, who was standing alone in the back of the end zone, with 4:06 left in the second quarter.

J.R. Jenkins gave the Herd a 10-7 lead on a 20-yard field goal with 9:34 left in the first half.

Smoker, on his second drive, led the Spartans on a 15-play, 75-yard drive, which ended with David Schaefer's 23-yard field goal with 1:34 left in the half.

Michigan State went ahead 17-10 midway through the third. Smoker escaped a sack and threw a 6-yard TD pass to Shawn Foster.

Schaefer's 23-yard field goal early in the fourth gave the Spartans a 20-10 lead.

Marshall sliced its deficit to 20-17 with 8:33 left on Leftwich's 4-yard pass to David Foye.

After Duckett's long touchdown run, Dawan Moss gave Michigan State a 34-17 lead on a 1-yard plunge. Leftwich threw a 4-yard touchdown pass to John Cooper as time expired.