Sunday night’s rout of Oakland resulted in plenty of smiles on the Redskins’ sideline, including Terrell McClain, left, Martrell Spaight (50) and Josh Norman. (John McDonnell/The Washington Post)

The Washington Redskins’ defense entered the season with a new coordinator, a new scheme and five new starters. This amount of turnover in one offseason created a feeling of optimism about an improvement in the team’s defense, a unit that has been mediocre at best under Coach Jay Gruden.

It also led many around the franchise to express the need for patience. Chemistry takes time, they pointed out, and it would be difficult to gauge how long it would take for Washington’s defense to jell.

After Sunday night’s performance, it seems it took three games. The Redskins produced their best defensive performance since Gruden was hired in 2014 by manhandling a talented Oakland Raiders offense in a 27-10 win and limiting it to just 128 total yards, the fewest allowed by the franchise since Oct. 12, 1992, and the fewest allowed by any NFL team in a game this season.

Yes, it was just one game. The mark of a good defense is consistency. But the Redskins’ defense took a significant step in the right direction in Week 3.

“When you’re talking about a defense that played that well, I think it’s impossible to say, ‘This is why,’” Gruden told reporters in a conference call Monday. “I think everyone played their part, played well, played hard, played with great passion and energy and played smart.”

The Redskins were clicking on all fronts. They tied a team record by limiting Oakland to a 0-for-11 rate on third downs, marking the first time they have held an opponent without a third down conversion since 2007. Washington finished last on third downs last season, allowing opponents to convert 46.6 percent of the time.

Gruden gave credit to defensive coordinator Greg Manusky for disguising his coverages and to all 11 defenders for their execution.

“That’s what I liked most about our defense,” Gruden said. “It was somebody different all the time. It was the interior pass rush. It was the edge pass rush. It was the coverage. It was tackling. It was pursuit. It was a little bit of everything. Fighting off blocks. There was some fundamental clinic tape in that game that I am very, very impressed with.”

Moving forward, Gruden said, “the standards are set very high around here now, and the ability to maintain it is going to be critical for us.”

The defensive line, which lacked depth and talent the last two seasons, and outside linebackers recorded four sacks and six quarterback hits against one of the best offensive lines in the NFL. Rookie defensive lineman Jonathan Allen and second-year defensive lineman Matt Ioannidis combined for 1½ sacks and three quarterback hits.

Defensive line coach Jim Tomsula, in his first season, has had a “huge” impact in Washington’s improvement at the position, Gruden said.

“Coach Tomsula’s coaching has really obviously been a key component of that, working with their alignments and their get-offs and their hand placement and fighting off blocks, double teams,” Gruden said. “He is the best in the business.”

The secondary was able to set the tone on the opening drive when rookie safety Montae Nicholson recorded his first interception, the first of three takeaways recorded by Washington. Nicholson has received more playing time at strong safety over the last two games, and it has resulted in two impressive outings to start his career. Nicholson, a fourth-round draft pick out of Michigan State, was limited throughout the offseason as he recovered from a shoulder injury.

“I think Montae really has been impressive, there is no doubt about it,” Gruden said. “You can just look at his stature coming out of the tunnel. He looks the part. He is physical. He is big. He can run. I just can’t say enough about what D.J. Swearinger means to Montae. As far as communication, giving him the confidence where he can play fast and free. Those two together are just a great tandem.”

Washington swarmed to the ball to limit Raiders running back Marshawn Lynch, who had 18 rushing yards, and Oakland’s ground game. It will need to do the same on Monday night against a talented Kansas City Chiefs offense that features plenty of speed in running back Kareem Hunt and wide receiver Tyreek Hill.

“It’s a major emphasis for us since [offseason workouts]. It’s a major emphasis in training camp, and it’s a major emphasis during the week — good fundamentally sound tackling and pursuit to the football,” Gruden said. “So hats off to the guys for executing the plan and playing well.”