Kansas City Chiefs running back Kolby Smith (21) gets past St. Louis' Marc Magro en route to a 14-yard, first-quarter touchdown. The Chiefs beat the Rams, 21-17, Thursday in Kansas City, Mo.

Kansas City, Mo. ? So what if it was all against the second team? The Kansas City Chiefs were badly in need of a confidence boost, and that’s exactly what they’ll take out of Thursday night’s 21-17 victory over a collection of St. Louis reserves.

“We know it wasn’t their ones. But you’ve still got to go out there and play and execute,” said Brodie Croyle, who directed two brisk first-quarter touchdown drives. “We wanted to come out here and put together a couple of good drives, and we were able to do that.”

The only projected Rams starter who did not take the night off in the final preseason game was center Nick Leckey. Everyone else was either a second- or third-teamer as coach Scott Linehan took a long look at players competing for the final roster spots.

The Chiefs (2-2), coming off a demoralizing 24-0 shutout at the hands of a Miami team that was 1-15 last season, had a more urgent craving. They were looking for confidence and momentum going into their regular-season opener next week at New England.

“You can’t put too much stock in it, and you can’t take too much away from it either,” Chiefs guard Brian Waters said. “It’s like last week – playing against Miami, it looked like they blew us out. We aren’t going to run around and think we’re kings of the world because we beat St. Louis tonight. Whoever is in front of you, you want to do the best you can.”

After the start of the game was delayed 1 hour, 26 minutes by a rain and wind storm, Marcus Riley recovered Dantrell Savage’s fumble on the kickoff and the Rams took a 3-0 lead on Josh Brown’s 35-yard field goal.

But the rest of the quarter belonged to the Chiefs, who snapped off two brisk scoring drives against the Rams reserves, capped each time by touchdown runs by Kolby Smith.

Croyle, who was handed the quarterback job in the spring, attempted only four passes and hit three for 42 yards. Smith ended a seven-play, 62-yard drive with a 14-yard run after Croyle scrambled for three yards and a first down.

Then against the second- and third-team defense of the Rams, the Chiefs moved 56 yards in nine plays for a 14-3 lead with 1:49 left in the quarter, with Smith scoring on a 4-yard run.

The only starters for the Chiefs not on the field for the first quarter were tight end Tony Gonzalez and running back Larry Johnson.

“I’m glad we did it because I think these guys deserved these extra snaps tonight, Linehan said. “To give them close to a full game’s work gives us a lot more to look at. We have some tough decisions to make and I think it will make it easier to give guys fair evaluations. Some guys helped themselves tonight.”

Reserve quarterback Damon Huard took over in the third period and made it 21-3 with an 11-yard touchdown pass to Bobby Sippio, one of several candidates for the Chiefs’ second wide receiver spot. Sippio beat veteran cornerback David Macklin in the end zone after the Chiefs had taken over on their own 31 when Brian Johnston recovered Travis Minor’s fumble.

The Rams (2-2) made it 21-10 with 10 seconds left in the half on Brock Berlin’s 20-yard scoring pass to Dane Looker.

In the first minute of the fourth quarter, Lance Ball’s 2-yard touchdown run capped a 12-play, 80-yard drive for the Rams that made it 21-17.

“We would have liked to have started faster and not given up the scores,” Linehan said. “They sustained some good drives and ran the ball well. What I was happy with was they settled down, and stopped them. The second half of the second quarter we played much better.”

Croyle admitted a good showing was important after the Miami shutout.

“That’s why (the first team) played a little longer,” he said. “We knew we weren’t as bad as we played last week. It was good for us to get back out here and get some confidence heading into our game with the Patriots.”