With the end zone a few strides away, Mark Ingram exhibited the explosive, tackle-breaking form that defined his Heisman Trophy career at Alabama.

Ingram highlighted his NFL debut with a 14-yard touchdown run on which he bounced off a defender and spun to keep his balance, and the New Orleans Saints rolled to a 24-3 victory over the San Francisco 49ers in the preseason opener for both teams on Friday night.

"Just being able to get in the end zone for the first time being an NFL player is special for me," said Ingram, who carried six times for 23 yards. "I just have to thank the line for blocking great. That's what really allowed me to get in. All I had to do was make one guy miss."

While Ingram's run helped him match the hype that comes with being a first-round draft choice, another rookie with far less pedigree had the most spectacular play of the night.

Joseph Morgan, a little known prospect who was undrafted out of Walsh University, scored on a 78-yard punt return during which he made one tackler miss with a spin move, slipped two other tackles as he made his way outside and then cut back across the field with breakaway speed.

"I really didn't think I was going to score at first," Morgan said. "After I got out to the (edge), the first thing I saw was the kicker, and they tell you if the kicker tackles you, don't even go back" to the bench.

David Akers hit a 59-yard field goal for San Francisco, a kick set up by rookie quarterback Colin Kaepernick's 28-yard scramble late in the first half.

Starters played less than a quarter, and defense dominated during that scoreless stint.

The game also marked the NFL head coaching debut of former Stanford coach Jim Harbaugh, a former NFL quarterback who will want to see better performances out of starter Alex Smith and his offensive line.

The Saints blitzed relentlessly and had six sacks in the first half.

"We had some errors in protection," Harbaugh said. "We've got to make them pay for that. We didn't capitalize on any of those opportunities. Therefore, they kept doing it."

The Niners did not get a first down on their first four series, three of which were thwarted by hits on Smith.

Will Smith had a sack and had another hit that caused an errant pass. Roman Harper had a sack and strip on a safety blitz, but the Niners recovered.

"There was some miscommunication, missed balls on passes," said Alex Smith, who was 2 of 7 passing for 10 yards. "It just wasn't good. I didn't feel that great about it. Obviously, it's the first preseason game. A lot of us have only had five or six practices under our belt."

The Saints' normally prolific first-team offense wasn't much better, failing to produce a first down on its first three series. The second possession ended when Drew Brees was nearly intercepted by safety Donte Whitner. The third stalled when a long pass over the middle went through receiver Robert Meachem's hands.

Brees' finished 1 of 4 for 6 yards before Chase Daniel came on to get New Orleans' first first down on a 19-yard scramble, which had 15 yards added for a late hit. That set up Garrett Hartley's 47-yard field goal for the first points of the game.

"We're not a team yet," Saints coach Sean Payton said. "We're a roster."

Kaepernick played most of the game for the 49ers, and his scrambling ability was evident as he wound up being the 49ers leading rusher with 47 yards. He was 9 of 19 for 117 yards passing but also was intercepted twice, first by cornerback Terrail Lambert and later by rookie linebacker Nate Bussey.

Daniel was 13 of 21 for 129 yards and led all three Saints scoring drives before being relieved by Sean Canfield in the final minutes. Joique Bell led New Orleans on the ground with 52 yards on nine carries.

Ingram's touchdown gave the Saints a 17-0 lead late in the first half. Saints reserve running back Chris Taylor added a 4-yard touchdown run in the fourth quarter for the final margin.

Morgan came into the game as a relatively unknown small college player who didn't even return punts at Walsh, where he was a receiver.

While Darren Sproles will likely return punts in the regular season, Payton did not want him to do so in the preseason opener, which gave Morgan his chance.

"I was scared, nervous because I haven't done punts since I was a senior in high school," said Morgan, who also had one catch for 21 yards.

Morgan is from Canton, Ohio, and played high school and college games on the same field where the Hall of Fame game is played. For one play in his pro debut, he even resembled some of the NFL greats enshrined in his hometown.

Notes: Payton said Meachem had a lower back strain, which resulted from a painful shot he took while trying to block on Daniel's long scramble in the second quarter. ... Saints rookie CB Johnny Patrick hobbled to the bench in the second half with a right knee injury and was later carted to the locker room. Payton said trainers believe it was sprain. ... The Niners were 3 of 16 on third downs. ... San Francisco's team quarterback rating was 25.6.