Selected with the 32nd and last pick in the first round of this year's draft, Ramsey came off the bench to lead the Redskins (2-3) to a victory at Tennessee last week, drawing praise from Coach Steve Spurrier.
But Ramsey's first start was a disaster from the outset as he was intercepted on three of his club's first four possessions. He completed 21 of 43 passes for 320 yards with one touchdown and was sacked seven times.
"Everything that could've gone wrong did," Ramsey said. "Coach said you just have to learn from it."
"Hopefully he could learn from this," Spurrier said. "That's what you have to do with these young guys. You have to let them play and learn from their mistakes."
Ramsey's early mistakes helped give New Orleans a 20-0 lead early in the second quarter.
While their defense made plays, the Saints also got plenty of highlights from Lewis, who scored on a 90-yard kickoff return in the second quarter before he brought back a punt 83 yards in the third.
Aaron Brooks passed for three touchdowns and Deuce McAllister rushed for 121 yards for the Saints (5-1), who scored more than 40 points for the first time since 1989. New Orleans remained tied with Tampa Bay for first place in the NFC South.
"I know I'm going to get my touches every week and I've got to take advantage of that," said McAllister, who carried 29 times and leads the NFC with 582 yards rushing. "We're doing a great job on offense of mixing up the run and the pass."
End Darren Howard had three sacks and free safety Jay Bellamy had two interceptions to lead the New Orleans defense.
"It was a good game for us, although we're not where we need to be yet," Saints coach Jim Haslett said. "The most impressive thing to me is that somebody new is stepping up for us every week. This week it was Michael Lewis and Darren Howard. That's what makes a good football team."
Bringing a bevy of blitzes, the Saints forced Ramsey into his first mistake on the Redskins' first possession when Bellamy stepped in front of pass intended for Rod Gardner and returned an interception to the Washington five-yard line.
But the Redskins defense stiffened and John Carney kicked a 21-yard field goal.
Ramsey's struggles continued on the next possession as strong safety Sammy Knight intercepted the rookie at the Washington 23 and a personal foul on Larry Moore moved the ball to the nine.
The Saints, however, could only convert the turnover into a 23-yard field goal by Carney, making it 6-0 with 6:49 left in the first quarter.
Ramsey could not be blamed for the next Washington miscue as running back Stephen Davis fumbled and tackle Grady Jackson recovered at the Redskins 30.
Four plays later, Brooks found tight end Boo Williams for a two-yard touchdown pass.
The Redskins committed their fourth turnover in as many possessions in the waning moments of the opening quarter when Bellamy intercepted Ramsey, giving the Saints the ball at the Redskins' 18.
"We made the plays today," Bellamy said. "We knew they would be throwing downfield because that's what Spurrier does. We knew we had to make plays."
In addition to their turnovers, the Redskins also committed six penalties for 56 yards in the opening quarter.
Brooks capped the short drive with a 17-yard touchdown pass to Joe Horn on the first play of the second quarter, extending the lead to 20-0.
Ramsey had another miscue wiped out on his next possession when Ken Irvin had an interception nullified by a holding penalty. Ramsey, who missed on his first five attempts, had his first completion with a short pass to Gardner with 14:32 left in the second.
After that completion, Ramsey directed a seven-play, 75-yard drive that Stephen Davis capped with a one-yard run with 10:39 left before halftime.
Lewis, who drove a beer truck before making the Saints roster last season, immediately gave the momentum back to his club. The speedster broke down the left sideline and accelerated down the field to complete his 90-yard return to make it 26-7.
"Every week we've been close," Lewis said. "We've always been one block away and last week I ran into my own guy on one of my returns. Today we made all the key blocks and I got sprung."
"We've been waiting for that all season," Haslett said. "He's been close in our first five games and we finally got the blocks to fall into place."
Ramsey engineered a 10-play, 81-yard drive that he capped with one-yard run and the Redskins then got a big defensive play to get back into the game.
Brooks drove the Saints into Redskins territory but had his pass intended for Jerome Pathon intercepted by backup strong safety Ifeanyhi Ohalete, who raced down the left sideline for a 78-yard touchdown, pulling the Redskins within 26-21 with 1:47 left in the half.
But Brooks atoned for the miscue on the next possession, finding Lewis with a 58-yard pass on third and 12 to the Washington 16. That led to Carney's 36-yard field goal as time expired in the half.
Lewis made another huge play early in the third. He took Bryan Barker's punt at his own 23, set up a wall of blockers and sprinted down the right sideline for an 83-yard touchdown to extend the lead to 36-21.
Cornerback Duane Hawthorne intercepted Ramsey at the New Orleans 31 with under three minutes left in the third.
On the first play of the fourth quarter, Brooks fired a 31-yard touchdown pass to Jake Reed, giving the Saints a 43-21 bulge.
Ramsey capped the scoring 46 seconds later with a 62-yard pass to backup running back Kenny Watson.
"We were fortunate to climb back into the game after all the adversity," Ramsey said. "Unfortunately, we were not able to sustain it."