The Houston Texans sprang a surprise ahead of the NFL draft by signing North Carolina State defensive end Mario Williams as the first overall pick.
Heisman Trophy winner Reggie Bush had been expected to be Houston's choice but the Texans have instead plumped for the 6ft 6in Williams.
He is the first defensive end to be top pick since Courtney Brown in 2001.
The New Orleans Saints opted for Bush while the Tennessee Titans, drafting third, chose quarterback Vince Young.
The Texans, who went 2-14 last season, also had first pick in 2002 in their first season.
In three seasons with North Carolina State, Williams started 34 of 36 games, making 175 tackles, 55.5 tackles for a loss and had 26.5 sacks.
He was considered the top defensive player available in this year's draft in New York.
Williams has signed a six-year $54m (£29.5m) contract and is confident he is worthy of being top pick.
"I have the size and the speed and the athleticism, and to find that in a defensive end is rare," he said. "You just don't see it all the time."
Bush dominated college football last season but has been embroiled in controversy this week over allegations involving rental payments for a home in which his parents lived.