COLUMBIA — Stephon Gilmore enrolled early at South Carolina in January 2009, having made the 70-mile trip south from Rock Hill, where he starred at South Pointe High and earned the state’s Mr. Football honors — as a dual-threat quarterback.

A little more than three years later, Gilmore became a wildly rich professional football player Thursday night, as a cornerback. The Buffalo Bills selected him 10th overall in the NFL draft, making him the fifth top-10 pick in USC history.

Eight picks later, former USC defensive end Melvin Ingram was selected by the San Diego Chargers, making Gilmore and Ingram the 10th and 11th first-round picks ever from USC.

The Gamecocks had two first-round picks in the same year just once before, 1981, when running back George Rogers went first and tight end Willie Scott went 14th. Before Thursday night, USC last had a first-round pick in 2006, when cornerback Johnathan Joseph went 24th.

As Gilmore walked onto the stage at Radio City Music Hall in New York and hugged NFL commissioner Roger Goodell, it might have been easy for the casual observer to overlook how Gilmore transformed himself into an elite corner after he arrived at USC.

That is as much a testament to his athleticism as his senior year high school quarterbacking statistics: 1,771 passing yards and 14 touchdowns, and 1,331 rushing yards and 23 touchdowns.

Also a standout defensive back in high school, he started all 40 games of his college career at corner. Then he left school a year early and ran the 40-yard dash in 4.4 seconds at the NFL combine — third-fastest among defensive backs, and a major development for the 6-1 Gilmore.

Largely because of his combine achievements, no prospect during the past two months rose in draft projections more than Gilmore. Mel Kiper Jr., ESPN’s draft analyst, said Gilmore’s rise also stemmed from NFL teams seeing him as “a great kid” with no character issues.

At USC, he had eight interceptions and 17 pass breakups — four and seven last season. Gilmore said he is confident he can play in the NFL because he competed against the Southeastern Conference’s elite wide receivers, such as Alabama’s Julio Jones, now with the Atlanta Falcons.

“I went against a lot of players who are doing well in the NFL and I did well against (them),” he said. “It’s very comfortable for me knowing I’ve played against (those players).”

In Buffalo, he joins a team that ranked No. 19 in the NFL last season with 232.1 passing yards allowed per game. The Bills’ starting corners last season were Terrence McGee and Drayton Florence, both of whom are 31 years old. The Bills picked a corner in the second round of last year’s draft — Aaron Williams. Bills general manager Buddy Nix likes the size and physicality Gilmore brings to his team’s cornerback group.

“You have to be big enough to match up against the (Patriots’) tight ends, especially in our division,” he said. “What (offenses) will do is spread you out with five receivers and then run the football.

“You have to have a guy who can tackle. And this guy is very physical as a corner.”

On ESPN’s broadcast of the draft, the analyst and former NFL coach Jon Gruden praised Gilmore, but said, “I think he needs some work in his back pedal and his fundamentals as a pure cover guy.”

The nits will inevitable be picked by many others. There will also be questions about where Ingram fits best as a pro — defensive end or outside linebacker. But San Diego general manager A.J. Smith said he likes that Ingram “can play all over the field.” USC frequently lined him up at defensive tackle to get better matchups in pass-rushing situations.

Above all else, Thursday was a celebratory night for USC, which is coming off its first ever 11-win season and enjoying the best back-to-back years in school history, with 20 wins in that span.

USC last had a player drafted as high as Gilmore in 2005, when wide receiver Troy Williamson went seventh. That fall, coach Steve Spurrier arrived in Columbia and built USC football to its present golden age. Players like Gilmore and Ingram helped deliver USC its long-awaited reward for years of angst. Thursday night, Gilmore and Ingram got rewards of their own.