GLENDALE, Ariz. — Bruce Arians didn’t know who his starting quarterback was going to be Sunday until about an hour before kickoff.

Just to be safe, the Arizona Cardinals head coach had three quarterbacks active for the game.

Listed as questionable after missing the previous three games with a nerve issue in his passing shoulder, Carson Palmer got the starting nod and threw two touchdown passes to help the Cardinals down the Washington Redskins 30-20 at University of Phoenix Stadium.

Palmer, who spent most of Friday in Denver getting treatment on the nerve by a specialist he discovered only a week earlier, completed 28 of 44 passes for 250 yards. He was not sacked and did not throw an interception.

For the first time since at least 1940, the Cardinals went five consecutive games without throwing at least one interception. First-place Arizona (4-1) holds a one-game lead over the defending Super Bowl champion Seattle Seahawks and the San Francisco 49ers in the NFC West.

“Today I had a really good idea (that I would play),” Palmer said. “I went through the whole week and threw very little on Wednesday, very little on Thursday and then felt pretty good on Friday and took about a quarter of the reps in practice and actually got in some 11-on-11 situations and seven-on-seven, and it felt good. It felt good Saturday, and it felt really good today.”

In addition to Palmer’s surprise return, the Cardinals forced four fourth-quarter turnovers and got three second-half field goals from rookie kicker Chandler Catanzaro.

Quarterback Kirk Cousins rallied the Redskins to a late touchdown, finding wide receiver Pierre Garcon on a 5-yard pass with 2:17 left to play. The play cut Arizona’s lead to 23-20. However, Arizona safety Rashad Johnson returned his second interception of the game 28 yards for a touchdown with 18 seconds remaining, sealing a fourth straight loss for Washington (1-5).

“It wasn’t what we wanted,” Cousins said of the Redskins’ play in the decisive fourth quarter, during which he was picked off three times. “The turnovers were costly. They just didn’t give us a chance to stay on the field. We had the players and were moving the football. We’ve got guys who can help us, but when you turn the ball over, you won’t give them a chance to show what they can do. We’ve got to be a lot better.”

The Cardinals snapped an eight-game losing streak head-to-head losing streak to Washington, which finished 2-for-10 on third-down conversions.

“I told our team after the game this game is not that hard to figure out,” Redskins coach Jay Gruden said. “The team that makes plays usually wins. The team that doesn’t turn the ball over usually wins. …

“We’re not doing anything. It’s a broken record every time I stand up here. Unfortunately, it’s on us as coaches. If we have to continue saying the same thing, we’re not obviously getting it across to our players.”

After Catanzaro hit a 49-yarder to put Arizona ahead 20-13 early in the fourth quarter, Cardinals cornerback Jerraud Powers stripped Redskins wide receiver Andre Roberts of the ball and safety Tyrann Mathieu recovered for the first turnover. Catanzaro then hit from 37 yards, making him 14-for-14 on field-goal attempts this season.

On Washington’s ensuing possession, Cousins was picked off by Johnson. It didn’t get much better from there for Cousins, who was intercepted yet again on the Redskins’ next drive, this time by Powers.

“The first one was a poor throw; high over the middle,” said Cousins, who finished 24-for-38 for 354 yards and two touchdowns. “I got off rhythm and just felt rushed and it threw me off where I wanted to be. That one was on me. The second one, it just got congested and it was just a tough deal the way it worked out. … The third one, I was just trying to get the ball downfield and did not see the defender.”

Palmer threw touchdown passes to wide receivers Michael Floyd and Larry Fitzgerald to help the Cardinals head into halftime with a 14-13 lead.

What the Cardinals said:

“I don’t think we’re going to put a huge emphasis on (being 4-1 and holding a one-game lead in the NFC West). We are where we are, and the rest of our division is where they are. … We’ve got a tough challenge going into Oakland to play there and find a way to get a win. We’re a long ways away from thinking about postseason and all the things that can happen. … Our focus needs to go right now on getting the game film and start watching Oakland and getting ready for that game.” — Quarterback Carson Palmer.

What the Redskins said:

“I’m looking at everybody (to help turn things around). I’m looking at coaches. I’m looking at all of the players. I’m looking at the staff. I’m looking at Mr. (Daniel) Snyder, Bruce Allen. This whole organization together is the only way we can get out of this. We start looking at one guy, then we’ve got problems. We’ve all got to dig ourselves out of this rut, and we will.” — Coach Jay Gruden.

What we learned about the Cardinals

1. Cardinals coach Bruce Arians has said it before: Carson Palmer is one tough cookie. The quarterback put himself through hell to get a faulty nerve to fire in his passing shoulder, but all the extra time and work paid off. “He’s a tough guy,” running back Andre Ellington said. “He’s our leader, and he wasn’t going to let us down.”

2. You just can’t run on the Cardinals. This is the first time since at least 1940 that the Cardinals held opponents to less than 100 rushing yards in each of the first five games of a season. “We shut down the run,” outside linebacker Sam Acho said, “but we gave up too many dink-and-dunk plays and had too many missed tackles, especially in the first half.”

–WR Larry Fitzgerald had his best game of the season, which has been a difficult one for the team’s career leader in every receiving statistic. “Mentally, I’ve always prepared myself for a big day,” he said. “If it happens, it happens. If it doesn’t, it doesn’t. I take my same approach every single week, every single day in my preparation. That doesn’t change.”

–S Rashad Johnson made two interceptions Sunday, one of which he returned 28 yards for a touchdown with 18 seconds to play. “The coaching tip is to get down,” Johnson said when asked if he should have just fallen to the ground. “But all I saw was green grass in the end zone. I assumed I could beat the offensive tackle to the end zone, so I took the opportunity to put the game away.”

–DT Frostee Rucker tweaked a calf injury but was able to return and finish the game. He was the only Cardinal who appeared to get hurt Sunday. That is significant because since the springtime, Arizona lost six of its front seven on defense.

What we learned about the Redskins

1. Third-down efficiency continues to haunt the Redskins. They entered the game converting just 34.4 percent on third down (21 of 61), and they finished 2-for-10 Sunday. “We just have to be more efficient,” wide receiver Andre Roberts said. “We’re getting plays, we just have to be more efficient — the receiver, the quarterback, the running back position — and make plays.”

2. Washington struggled running the ball all season, and Sunday was no different. Ranked 21st in the league and averaging 104.8 yards per game, the Redskins finished with just 72 yards against Arizona. Running back Alfred Morris was held to 41 yards on 13 carries. “I have no clue, honestly,” Morris said. “We’re nitpicking. We’re trying (to point out) the smallest of things, just trying to work on it in practice and get it to translate in the game. We had little flashes here and there, and we just can’t keep it going. I really don’t know why, but we have to figure it out.”

–OLB Ryan Kerrigan led the team with nine tackles and added a forced fumble and half a sack, but he left the game in the second half after experiencing concussion symptoms. He later was cleared to return, but he will be re-evaluated this week.

–WR DeSean Jackson’s average of 17.2 yards per reception since he entered the NFL in 2008 ranks second among players with at least 300 receptions. He improved his average Sunday by catching three passes for 115 yards — 38.3 yards a catch.

–LB Brian Orakpo dropped an easy interception of a Carson Palmer pass in the fourth quarter when the Redskins were trailing by seven. He has been dealing with a hand injury but didn’t want to make any excuses. “I just missed it,” he said. “It’s just something I’ve got to make. I’ve got to make that play.”