Last Monday night, Jarryd Hayne made his NFL debut as a running back for the San Francisco 49ers. It was an inauspicious debut, to be sure, featuring a fumble on his first punt return and just 13 yards collected on four carries. But for Hayne, being on the Niners' 53-man roster for their season opener on Monday Night Football was an achievement in itself.

It's not that the 27-year old Australian isn't a good athlete. In fact, it was his superb athleticism that got him noticed as a two-time Australian Rugby League Player of the Year and that helped turn his desire to play American football from silly fantasy into reality (although he did have to take a pay cut to make it happen). Still, few expected Hayne, who had never played a down of organized football before training camp, to survive within the elite, hotly competitive NFL. And yet, there he was, having made the cut after an eye-opening preseason in San Francisco.

Hayne's Australian-rugby-star-turned-American-football-player story is the stuff of cheesy Disney films. But he's hardly the only athlete to have taken an unlikely path to a sport's highest level. It's never easy to break through and become a professional athlete, but these 13 people had more obstacles to overcome in order to reach the summit - and were still able to do so. Here are the 13 most unlikely success stories of people who managed to ascend to the pinnacle of their sport.

13 13. Randy Smith

Before there was Deion Sanders and Bo Jackson, Randy Smith starred as a multi-sport athlete at Buffalo State College, earning All-American honors in basketball, soccer and track & field. Even so, Smith didn't exactly project as a blue chip NBA superstar, playing forward but measuring in at just 6'3". Accordingly, he had to wait until the seventh round (104th overall) before he was taken by the Buffalo Braves in the 1971 NBA Draft. Not only did Smith enjoy a lengthy career that included two All-Star appearances and a (temporary) reign as the league's iron man, but he flirted with playing in the North American Soccer League on multiple occasions.

12 12. Dino Ciccarelli

Injuries and a diminutive 5'10" stature left scouts less than enamored with the prospect of drafting Dino Ciccarelli in 1979, despite his 72 goals and 70 assists just one season prior. Upon reaching the NHL after signing an entry level contract with the Minnesota North Stars, Ciccarelli quickly went about proving his detractors wrong. In just his second NHL season, the right winger led his team with 55 goals and participated in his first of four All-Star Games. He would go on to enjoy a Hall of Fame career and become the highest-scoring undrafted player in league history.

11 11. Michael Oher

Offensive tackle tends to be a relatively anonymous position in football. Not so for Michael Oher, whose story was brought to the big screen in "The Blind Side". Although surely dramatized for Hollywood, there was something undeniably compelling about the story of a gentle giant who grew up in poverty but was welcomed into the home of a wealthy Tennessee family. Oher overcame academic struggles and a difficult childhood to earn a scholarship from the University of Mississippi and, later, a first round draft selection at the 2009 NFL Draft. He was taken by the Baltimore Ravens, where he later won a Super Bowl.

10 10. Jeremy Lin

Linsanity captured a beautiful, fleeting moment in time early in 2012, the product of an unlikely string of red hot play from a point guard who had been just hanging on to a roster spot. But that wasn't the only time Jeremy Lin overcame the odds in his career, being one of four Harvard alums and one of nine Asian-born athletes to reach the NBA. That all went into what made the undrafted Lin so very compelling during that month-long stretch in which he averaged 22.5 points and 8.7 assists while leading the New York Knicks to a 9-3 record.

9 9. Billy Miske

For Minnesota-born boxer Billy Miske, a diagnosis of a kidney disorder called Bright's disease was doubly hard to take. On one hand, it meant that he was being given just five years to live by doctors. On the other hand, it seriously threatened his boxing career, which provided the precious little cash needed to help ease his debt and support his family. Against doctor's orders, Miske continued to fight. On death's doorstep, he took a fight against highly regarded heavyweight Bill Brennan in order to give his three kids a dream Christmas. One unlikely knockout win later and Miske had given his children their dream Christmas - days before succumbing to his disease.

8 8. David Eckstein

Colleges weren't exactly hot on the chase for 5'7" David Eckstein coming out of high school. He received no athletic scholarship offers, instead earning an academic scholarship at the University of Florida, where he secured a spot on the baseball team as a walk-on. As a Gator, Eckstein played well enough to earn athletic scholarships in his junior and senior seasons before being drafted in the 19th round (581st overall) of the 1997 amateur draft. Not only did Eckstein make it to the majors, but he carved out a respectable 10-year career that included a World Series MVP award in 1996 as a member of the St. Louis Cardinals.

7 7. Mark Herzlich

There wasn't much that could get in the way of Mark Herzlich as he drew plenty of NFL attention during a celebrated Boston College career that saw him feted as an All-American and a Butkus Award finalist. Cancer, however, could get in the way. Before the 2009 season, Herzlich announced that he had been diagnosed with Ewing's Sarcoma, a rare form of bone cancer. Four months after the initial diagnosis, the linebacker was able to announce that he had beaten the disease and was cancer-free. Despite not getting selected in the 2011 NFL Draft, he won another uphill battle by earning a roster spot with the New York Giants after signing as an undrafted free agent.

6 6. Vince Papale

It's probably safe to assume that few NFL football players went to colleges without football programs, but Vincent Papale's path to the NFL was anything but clear, even in college. After attending Saint Joseph's University as a track standout, Papale caught on with a semi-pro pigskin club while working as a high school teacher. He made a strong impression during a tryout with the Philadelphia Bell of the World Football League and garnered an audience with Philadelphia Eagles head coach Dick Vermeil. After impressing at football's highest level, he made the team at age 30, becoming the oldest rookie in NFL history to play without the benefit of college football experience.

5 5. James J. Braddock

It's hard to fathom in today's era of highly lucrative prize fights the dilemma that James J. Braddock faced when he was forced to step away from boxing and work as a longshoreman in order to support his family during the Great Depression. What's more remarkable about the story of the so-called "Cinderella Man", however, is what he accomplished upon returning to boxing in 1934, five years after his departure. After three surprise victories, Braddock shocked the heavily favored world champion Max Baer to win the heavyweight championship.

4 4. Jim Morris

The third consecutive athlete story that doubles as a Hollywood film, left-handed pitcher Jim Morris reached the majors as a 35-year-old rookie with the Tampa Bay Devil Rays in 1999. The one-time New York Yankees draft pick had given up his big league dream and settled into life as a high school science teacher when he agreed to take part in a major league tryout if the team he coached won the district championship. They held up their end, so he joined an open tryout, where he threw 12 straight 98-mph fastballs. After pitching well at Triple-A, Morris struck out Royce Clayton in his major league debut and would go on to appear in 20 games for the Devil Rays.

3 3. Francis Ouimet

Brookline, Massachusetts native Francis Ouimet is often referred to as the "father of amateur golf" thanks to his victory at the 1913 US Open, widely viewed as one of the biggest upsets in golf history. Ouimet was an amateur local player who planned to caddy at the 1913 Open when the president of the United States Golf Association approached him to participate. Despite his high level of familiarity with the course, the 20-year-old Ouimet seemed out of his element in the presence of world class British golfers Harry Vardon and Ted Ray. However, he managed to top both men in an 18-hole playoff to reign as an unlikely champion.

2 2. Jim Abbott

There may never be another major league pitcher like Jim Abbott, a one-handed hurler who rode a unique fielding technique to a productive 10-year career. Abbott would rest his glove on the stump on his right arm while pitching, only to rapidly switch it onto his left hand once the pitch was thrown. Despite the challenging nature of compensating for his physical disability, Abbott still joined exclusive company when, on September 4th, 1993 at Yankee Stadium, he threw a no-hitter against the Cleveland Indians.

1 1. Kurt Warner

One year, Kurt Warner found himself bagging groceries to supplement his paltry income as an Arena League Football player. Warner signed his first NFL contract with the St. Louis Rams in 1998, primarily as an insurance option at quarterback. However, once fellow quarterbacks Tony Banks and Steve Bono were cut after the 1998 season and incumbent starter Trent Green tore his ACL in the '99 preseason, the club turned to Warner. All he did upon taking the helm was engineer an airborne offensive attack nicknamed "the greatest show on turf" that spawned a Super Bowl championship and two MVP awards.