Pierce didn't stop until he reached the end zone.
The play in the first quarter contributed to the Raven's 25-15 win Sunday over the Cleveland Browns.
ANd Pierce celebrated the career moment by sharing a flying bump with wide receiver Torrey Smith.
"I was overly excited," Pierce said. "I didn't know what to do."
A third-round draft pick, Pierce is accustomed to scoring touchdowns as he ended his career at Temple with a school-record 54 touchdowns.
However, Pierce said he has special plans for the football he carried 12 yards to give the Ravens a 14-0 lead.
"It's going to my mom," he said. "Hopefully, it's the first of many."
As the primary backup to Pro Bowl running back Ray Rice, Pierce is known more for his power at 6-foot, 218 pounds. On Sunday, though, he also showed a burst of speed to get around the perimeter for the touchdown.
"It was a kick, so I had angles," Pierce said. "I had choices. I trusted my speed and tried to get outside. I've just been waiting and trusting my coaches and trusting the play calling. I just wanted to be a part of it."
Pierce had a career-high seven carries for 26 yards.
With his knowledge of the playbook increasing, Pierce is working on becoming a more decisive, deliberate runner.
"In practice, my tempo has been crazy and I go as fast as possible," Pierce said. "I wanted to try to make sure I had everything down pat."
Changing on the fly
After pointing out last week that Flacco had checked out of some running plays for Rice during the loss to the Texans, offensive coordinator Cam Cameron credited the quarterback for some timely audibles that benefited the running game.
Rice rushed for 98 yards and a touchdown after being held to nine carries and 42 yards against the Texans.
"Joe did a phenomenal job of audibling to some runs and got us a couple of big runs there," Cameron said.
Cameron also noted that Flacco audibled to a short lob pass for a two-point conversion to wide receiver Anquan Boldin in the back of the end zone for the Ravens' final points.
"That was a great call by Joe," Cameron said. "That was great execution by him and Q."
Suggs silenced by Thomas
It was a much quieter second game back for Pro Bowl outside linebacker Terrell Suggs.
After recording a sack against the Houston Texans during his season debut following a partially torn right Achilles tendon, Suggs was shut out by Browns Pro Bowl left offensive tackle Joe Thomas.
He finished with four tackles and one quarterback hit, occasionally shifting to the left side to try to rush against rookie offensive tackle Mitch Schwartz.
"It's always tough working on their offensive line," Suggs said. "Joe is a great tackle."
Although Suggs didn't generate much of a pass rush, the reigning NFL Defensive Player of the Year was solid against the run as he played significantly more snaps than he did in Houston when he was utilized on 44 of 76 plays.
"I'm building on it," Suggs said. "I'm getting confidence back in the tendon. I'm still not there yet, but I'm going to get there. I can guaranteed you one thing: When we get to them games that count, we should be where we need to be."
One of the most penalized teams in the NFL, the Ravens had another rough game with the officials Sunday.
They were flagged nine times for 82 yards. That included coach John Harbaugh being hit with an unsportsmanlike conduct bench penalty when he complained about free safety Ed Reed being crushed by wide receiver Josh Gordon on a crack-back block.
Afterward, Harbaugh acknowledged he was in the wrong as the officials already had penalized Gordon. Harbaugh was unaware that the officials had made the call he wanted.
"That was on me," Harbaugh said. "I wanted the crack-back call. I didn't see the flag. I was drawing it to his attention, with a little too much enthusiasm obviously, and they got me rightly so."
Then, Williams got up and darted around the field after retreating at first for a 26-yard return.
"They tried to sneak the tight end from the opposite side to my side, and I saw him and I remember they got us on that a couple of times on that play the first time," Williams said. "Weeden told me after the game he was trying to throw it away because the receiver didn't even look for the ball. I told him after the game to just throw it way out of bounds because you never know what will happen.
"He's a good quarterback. He has a huge upside. He's the future of that team. I think they made the right decision by going to get him in the first round."
Debut for Jah Reid
Inactive for the first seven games due to a strained right calf, offensive lineman Jah Reid made his season debut.
He lined up as an extra tight end in jumbo packages and took a few snaps at offensive guard.
"It feels good to go out there and help the team any way I can," said Reid, a 2011 third-round draft pick. "I did all right. You improve every week. It was great to be out there. I had some good plays, so it's something to build on."
The Ravens reported no injuries, and Harbaugh was relieved that nothing serious occurred.
"I don't think we had anything," he said. "I know we didn't have anything major. I don't think we had any issues coming out of the game, so that's good news."
Pro Bowl offensive guard Marshal Yanda briefly headed to the locker room to have his right knee re-taped.
"Yep, it feels great," Yanda said after the game.
Pro Bowl defensive tackle Haloti Ngata started despite not practicing twice last week due to a right shoulder injury and a sprained right medial collateral ligament.
Although Ngata registered no takcles for the first time this season, the three-time Pro Bowl selection pressured quarterback Brandon Weeden into an interception.
The Ravens deactivated rookie cornerback Asa Jackson, rookie running back Bobby Rainey, offensive guard Ramon Harewood, wide receiver and kick returner Deonte Thompson, tight end Billy Bajema, defensive end Pernell McPhee (right knee, thigh) and defensive tackle Bryan Hall. ... Starting in place of McPhee at left defensive end, Arthur Jones had four tackles and two quarterback hits. ... Ravens inside linebacker Dannell Ellerbe was penalized for unnecessary roughness for his hit on rookie running back Trent Richardson, a play that could draw a fine from the league office. Meanwhile, Browns safety T.J. Ward was flagged for roughing the passer for hitting Flacco in the head on a blitz.