South Carolina is 0-3 in Southeastern Conference play for the first time since Steve Spurrier's first season as head coach in 2005.
The Gamecocks (2-3, 0-3) fell to Missouri (4-1, 1-1) 24-10 Saturday, giving the Tigers their first conference win.
"Missouri outplayed us," Spurrier said. "That's all you can say. They played with no turnovers. They ran the ball better than us. Give those guys credit."
It was the first time in SEC history that two true freshman quarterbacks started in the same game.
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Lorenzo Nunez threw three interceptions in his second start for the Gamecocks, finishing 15 of 24 for 172 yards and a touchdown. He also led the team in rushing with 15 carries for 60 yards.
"We wished he would have thrown those to a little different spot," Spurrier said of Nunez's interceptions. "We've got to get the ball to the open guy at the right time. We didn't do that."
Nunez's only touchdown pass was nearly intercepted by Aarion Penton near the goal line, but bounced off his hands into the hands of Shon Carson, who crossed the plane for an 8-yard score.
Nunez's play would be overshadowed by Missouri freshman quarterback Drew Lock. Lock started in place of Maty Mauk, who was suspended Tuesday for violating team policies. He completed 21 of 28 passes for 136 yards and two touchdowns, and became the first freshman to start at quarterback for Missouri since Corby Jones in 1995.
Missouri coach Gary Pinkel was pleased with Lock's debut as a starter.
"Drew really did some good things for a young player," Pinkel said. "I thought he really carried himself well."
Pharoh Cooper led the Gamecocks in receiving with nine catches for 102 yards. David Williams had nine rushes for 40 yards, but South Carolina was limited to just 5 yards rushing in the first half.
"The only thing we had was Lorenzo," Spurrier said of the Gamecocks' run game. "It's a huge difference when you can't run the ball in. We're struggling doing that."
Missouri captains Kenya Dennis and Ian Simon recorded their first interceptions of the season, as did defensive end Walter Brady. Brady also had two sacks, both on third down.
"Turnovers are what really lost us the game," Cooper said. "We cannot have turnovers every possession we have."
Cooper said the interceptions affected Nunez's psyche.
"It is about confidence," Cooper said. "He came out in the second half and had three interceptions back-to-back. He's a young guy. He just has to relax back there."
Bluffton's Shameik Blackshear made his first two tackles as a Gamecock.
Missouri gained a season-high 163 rushing yards on 42 attempts. Ish Witter had 17 carries for 98 yards and his first touchdown of the season. Russell Hansbrough had 11 rushes for 43 yards.
Nate Brown had six catches for 33 yards and two touchdowns. Brown is the team's leading receiver with 17 catches for 192 yards and four touchdowns on the season.
"Once the offense got going, we got our tempo going and everyone was a little more relaxed," Brown said. "When you get into a rhythm, it relaxes everybody on the offense and just kind of keeps them focused on their job."
Kentrell Brothers started for Missouri and recorded seven tackles, including 1 1/2 for loss. Brothers leads the nation in tackles with 59, but was listed as questionable heading into the game after injuring his left ankle in a 21-13 loss at Kentucky last Saturday.
The Gamecocks will return home to face No. 9 LSU next Saturday. Missouri will host No. 25 Florida in the school's 104th homecoming.