Sanchez was selected as the team's starting quarterback by coach Rex Ryan on Wednesday, making him the first rookie slated to open a season under center for the Jets.
"This comes with a lot of responsibility," a beaming Sanchez said. "As happy as I am, I know that this is just the beginning and I'm just excited, really excited, to get to play with such great players."
The fifth overall draft pick out of Southern California beat out Kellen Clemens for the job and will make his regular-season debut at Houston on Sept. 13.
"This is something I've always wanted to do and dreams are coming true now," Sanchez said. "It's a special opportunity."
Ryan, who made the announcement after practice, said early in training camp he'd like to make a decision on a starter by the Jets' third preseason game.
"I think Mark gives us the best opportunity to win," Ryan said, "and I think that's what I owe this franchise."
The Jets' next preseason game is Saturday night against the Giants.
Sanchez replaces Brett Favre as the starter after generally showing poise and solid decision-making skills during training camp.
Ryan met with Sanchez and Clemens on Wednesday morning and told them of his choice.
"I'm glad the decision was made earlier rather than later," said Clemens, who added he thought the competition was fair.
The last time a rookie started a season for the franchise was in 1960, when Dick Jamieson quarterbacked the then-Titans. Joe Namath didn't start until the third game of his rookie season in 1965. Matt Robinson was the last rookie quarterback to start a game for the Jets in 1977.
"I feel very comfortable and confident in my decision," Ryan said.
Sanchez won't have an easy welcome to the NFL, though, facing a tough Texans defense in the opener, followed by home games against New England and Tennessee.
Sanchez struggled early in his start at Baltimore in a preseason game Monday night, but threw a touchdown pass to Leon Washington to cap his final series. Sanchez was 3-for-8 for 43 yards and had an interception -- his first pass of the game -- returned for a touchdown.
"I think it's not about just one game and I think that defense, I'm not making excuses here, but they're a great group," Sanchez said. "They make veteran quarterbacks look silly out there. It wasn't my best game, that's for sure. Do I need to improve? Absolutely."
Meanwhile, Clemens was 5-for-10 for 60 yards and a score, but also had an interception returned for a TD. Entering his fourth season with the Jets after being a second-round pick in 2006, also had a solid but unspectacular camp, but threw 12 interceptions compared to the rookie's five during practices.
"I'm disappointed overall because I think I left some plays out there that I should've made, both in practice and in the games," Clemens said. "It's Mark's job and I'll support him moving forward."
It was the third quarterback competition for Clemens, once considered the team's future QB, but he lost out to Chad Pennington in 2006, Favre last summer and now Sanchez.
"Each competition is different," Clemens said, "but it never feels good to be the guy who'll be holding the clipboard on Sept. 13."
Clemens, a free agent after this season, said he believes he can start in the NFL -- whether it's in New York or elsewhere.
"It's a bump in the road," he said. "It's not the end of the road."
The Jets traded up in the draft to acquire the fifth overall pick from Cleveland and former coach Eric Mangini. Just a few weeks later, the Jets signed Sanchez to a five-year deal that could be worth up to $60 million, including $28 million guaranteed.
Sanchez was already being touted as the new face of the franchise and it appeared it was his job to lose after that. Clemens didn't help his cause by being just as good as the rookie, but not clearly better than him.
It was expected if the competition was close, the organization would move forward with Sanchez. Ryan made it clear after the team drafted Sanchez that he wouldn't be afraid to start a rookie quarterback, particularly after watching Joe Flacco lead the Ravens to the AFC championship last season.
"At the end of the day, I'm going to rely on my instincts, just a gut feeling that I had," Ryan said.