Redskins quarterback Dwayne Haskins unleashes a 55-yard touchdown pass in the second quarter of Thursday’s preseason loss to Cincinnati. (Toni L. Sandys/The Washington Post)

The ball flew from Dwayne Haskins’s hand, tracing through the Thursday night lights like a laser, his first Redskins touchdown pass landing in the arms of a racing Robert Davis. And, if for a moment, Washington could see its football future in the present: a 55-yard pass that roared past the Cincinnati defense in the second quarter of the Redskins’ 23-13 loss to the Bengals.

“It was exhilarating. It was exciting. It was fun. I will never forget it,” Haskins said later with a smile.

It has been a hard summer for the Redskins’ first-round pick, the draft’s 15th selection. Haskins’s training camp has had more wayward passes and balls thrown into defenders’ arms than highlight moments. Despite the flood of excitement that normally follows a first-round quarterback, he had quickly fallen behind Case Keenum and Colt McCoy in the battle to be Washington’s starting quarterback this fall.

But with McCoy still slow to recover from offseason surgeries — and not a consideration for a starting job until he gets healthy, Redskins Coach Jay Gruden said after Thursday’s second preseason game — the Redskins had little choice but to give Haskins nearly three quarters against the Bengals. His fourth throw turned out to be his best, coming as he was nearly being pulled down for a sack and spotted Davis — running open — for the touchdown.

Much like Haskins’s first game last week at Cleveland, Thursday was a mix of good and bad. The touchdown was offset by some other missed throws, including one heaved too far for an open Cam Sims running fast down the right sideline. He also was hit from behind by the Bengals’ Jordan Willis while making a third-down throw inside his own 20. Willis’s arm jarred the ball from Haskins’s hand as the quarterback appeared to start his throw, sending it skittering to the right where it was recovered by Cincinnati. A video review upheld the play as a fumble, not an incomplete pass.

Unlike last week, when he was intercepted twice, Haskins didn’t have a pass picked off, and this stood as an improvement. For the night, he was 7 for 14 for 114 yards and the one touchdown. He was sacked three times for a loss of 19 yards but also scrambled six yards from a near sack. His passer rating was 101.5.

While Gruden said he loved Haskins’s touchdown throw, he said he also liked the way Haskins handled the pass protection “to get that extra beat of time.”

“Dwayne shows flashes,” Gruden later added. “There’s a couple balls that he rushed a little bit, a couple of shots he rushed a little bit, and I think he missed a couple of shots . . . didn’t put enough air under there. This is all a process for him, and it’s good to see him get out there, take some hits here and there, have him do the protections, getting the running game going, calling the play. It’s just the presentation I’m interested in, how he handles himself.”

Keenum did not have a brilliant touchdown throw like Haskins, but he didn’t have the lows, either. In three series, two of which were with some members of the starting offense, he was 3 for 7 for 52 yards. He made two nice passes in his first drive to Vernon Davis and Brian Quick and probably would have had a better statistical performance if Quick had held on to another ball and the drive wasn’t cut short by offensive penalties. He also avoided making any turnovers.

But the early highlights for Washington came while its defense was on the field. Gruden finally unleashed his starting defense after holding it back in training camp and sitting it in last week’s preseason opener. After winning Thursday’s coin toss, Gruden sent his defense onto the field to start the game, and the starting defensive players stormed out aggressively — perhaps too aggressively.

They swarmed Bengals quarterback Andy Dalton and landed hits on Cincinnati ball-carriers, but the blows drew flags for their violence. Safety Montae Nicholson was penalized for lowering his helmet at running back Joe Mixon, defensive tackle Jonathan Allen was penalized for unnecessary roughness for flinging running back Giovani Bernard to the ground, and cornerback Josh Norman was given a roughing penalty on an incomplete pass and then handed an unsportsmanlike conduct penalty for arguing the call.

The Bengals had just 17 yards on their first drive but gained 45 more on penalties. All of it was for naught, however, because Nicholson intercepted a Dalton pass near the goal line that had been tipped by defensive lineman Daron Payne and ran 96 yards for a touchdown.

“To recover from those penalties and get the pick-six was big time,” Gruden said.

The Redskins’ defense can’t score all the team’s touchdowns, however. And while Haskins’s entrance in the second quarter of his FedEx Field debut barely drew a ripple from the sparse crowd, his touchdown throw provided a glimmer of hope of what the rookie could one day provide.

Washington’s coaches remain optimistic about Haskins’s future. They remain impressed with the way he has been focused and shrugs off bad performances. They say his stumbles are normal for a quarterback with his experience and to expect something more dazzling would be unrealistic. They expect mistakes. That’s what games such as Thursday’s are all about.

“It’s fun to watch him right now,” Gruden said. “He’s a work in progress. He’s going to continue to get better and better.”

On a night when Gruden used a new rule to challenge two pass interference calls against the Redskins and lost both (while watching as Cincinnati Coach Zac Taylor successfully challenged to have one applied against Washington), the team’s future quarterback made several bad throws and one great one. More than likely it’s that touchdown pass that everyone will remember from an otherwise forgettable evening for Washington.