In their dress rehearsal for the regular season, Robert Griffin III and the Washington Redskins’ offense put on their most well-rounded performance of the preseason Saturday, defeating the Indianapolis Colts, 30-17, at FedEx Field.

The previous week in a loss to Chicago, the Redskins failed to protect their quarterback or put together a consistent rushing attack. But on Saturday, Washington’s starting offense assembled two scoring drives that resulted in one touchdown through the air and one on the ground. The offensive line didn’t surrender a sack and it paved the way for a 100-yard rushing day by rookie Alfred Morris.

Griffin completed 11 of 17 passes for 74 yards and a touchdown and had a quarterback rating of 93.8 as he played in front of a FedEx Field crowd (announced at 60,047) for the first time in his career. Morris carried the ball 14 times for 107 yards and a touchdown. The Redskins went 4 for 6 on third down conversions in the first half.

“He looked a lot more comfortable. I think with every game, he will feel more comfortable,” Redskins Coach Mike Shanahan said of Griffin. “I thought we had a chance for a couple big plays that we just missed, which is always disappointing. But we were right there, just a hair away. I just liked the effort of our overall football team. Any time you’re able to run the football and average over seven yards a carry with your first unit, you’ve got a chance to do something special.”

The Redskins also showed better defense than they had at Chicago. They limited Andrew Luck and the Colts’ starters to one touchdown, sacked the first overall pick twice and held Indianapolis’s starters to 22 rushing yards.

Luck looked like the polished prospect the Colts believed him to be when they made him the first overall pick of the 2012 draft. He completed 14 of 23 passes for 151 yards and a touchdown and had a quarterback rating of 94.7 against the Redskins’ starters.

Griffin and Washington’s offensive starters got going in their third series of the game.

On a possession that began at the Washington 34-yard line, Griffin completed all three of his pass attempts and marched his team 66 yards for a score. Griffin first completed a four-yard pass to tight end Chris Cooley — Cooley’s first target and reception of the preseason — then took the snap, rolled to his right to avoid the rush and connected with wide receiver Josh Morgan for an 11-yard gain. Later Griffin hit Pierre Garcon down the center of the field on a 19-yard strike.

Morris broke a 17-yard run before he was knocked out of bounds at the 2-yard line, and then powered his way into the end zone on the next play to cap the drive.

“I feel phenomenal, thankful that I finally got one,” Morris said of his touchdown. “My auntie was joking, she told me that I was going to get my first touchdown today, and I definitely did, so it was exciting.”

The Colts responded with an 11-play, 80-yard drive that climaxed with a 31-yard touchdown pass on third down from Luck to T.Y. Hilton, who beat free safety Madieu Williams down the sideline and made the catch.

“We give up some third downs, obviously gave up the big play,” linebacker London Fletcher said. “I thought we did a lot of good things. Obviously there were some things we’d like to tie down. There’s always room for improvement. But I thought for the most part, we did a good job.”

Washington answered, chewing up six 6 minutes 18 seconds on 12 plays, the longest possession by Washington’s starters this preseason.

On that series, running back Tim Hightower made his return to the field 10 months after his 2011 season ended with a torn ACL in his left knee. Hightower was held out of the team’s offseason practices and spent the first month of the preseason limited to individual drills. He went through his first full-contact practice Monday and received clearance to return.

On the Redskins’ first three possessions, Hightower played as the third-down back, but didn’t have a target or a carry. Ten plays into the team’s fourth series, he took his first handoff since Oct. 23, 2011.

At the Indianapolis 23, he ran to his left, bounced to the outside, then cut back to the inside before he was tackled at the 5-yard line. Two plays later — after a one-yard Hightower gain — Griffin took the shotgun snap, rolled to his right and hit Santana Moss in the front of the end zone for the rookie quarterback’s second touchdown pass of the preseason.

Hightower finished the game with five carries for 28 yards and a catch for a one-yard gain.

“It was special. I think I hugged my coach and the trainers about 18 times,” Hightower said. “It’s been a long road. . . . It’s the first step. It’s not the end of the road. . . . It’s a lot of improvement. But I’m in the ballgame, I’m not on the sideline, and that’s all you can ask for.”

The Colts threatened to score after getting the ball with 1:09 left in the half. Indianapolis reached the Washington 43-yard line, when, with five seconds left, Luck took a shot at the end zone. But Redskins safety Tanard Jackson delivered a jarring hit on wide receiver Kris Adams, knocking the ball out of his hands for an incompletion and preserving Washington’s 14-7 lead at halftime.

Washington’s defense accounted for the first points of the second half. On third-and-16 from the Indianapolis 9-yard line, backup outside linebacker Chris Wilson sacked second-string quarterback Chandler Harnish in the end zone for a safety that put Washington up 16-7.

The Redskins found the end zone again on a 13-yard touchdown pass from Rex Grossman to D.C. nativeJosh Morgan for a 23-7 lead with just more than two minutes left in the third quarter.

Grossman, who struggled mightily in the preseason opener, continued his strong outing, completing all four passes on the next possession, including a 12-yard touchdown strike to Dezmon Briscoe.Grossman finished the game 8-for-8 for 127 yards with two touchdown passes and a quarterback rating of 158.3.

The Redskins conclude the preseason Wednesday at home against Tampa Bay. Their starters aren’t expected to play in that game.

“If we’re going to finish with this performance,” Griffin said, “this was a good way to finish it.”