The 31-year-old quarterback with a history of concussions threw a key block near the goal-line on Stefan Logan's 54-yard touchdown run in the second quarter as the Lions rebounded from an early 12-1 deficit to defeat the Edmonton Eskimos 43-22 and snap a three-game losing streak.
"You need that type of play. You look at the good quarterbacks in this league and that's the way that they play. That's the CFL," said Pierce, who finished with three touchdowns through the air and another on the ground. "I've had so many knocks on me for doing stuff like that throughout my career. But I'm a football player.
"I've been in this league for nine years and if they're expecting me to change now, it's not going to happen."
Pierce replaced the ineffective Thomas DeMarco at the start of the second quarter and connected on two short TDs to Andrew Harris and a long bomb to Emmanuel Arceneaux for the Lions (10-7), who were already locked into the third seed in the CFL's West Division playoff picture coming into the game.
Despite those numbers, it was Pierce's block that everyone was talking about.
"That gives your sideline a tremendous boost," said Lions coach Mike Benevides. "He's a guy that's gone to war and understands the value of it."
With one game to still go in the regular season, B.C. will visit either the Saskatchewan Roughriders or the Calgary Stampeders in the semifinal round on Nov. 10.
"Buck came in and he was lights out. I thought he did a phenomenal job of orchestrating the offence," said Lions defensive end Keron Williams. "(Buck) has that grit, he has fight in him. He makes plays out of nothing."
Mike Reilly, who signed with the Eskimos (3-14) in the off-season after three years with B.C. as a backup, was 20-of-34 passing for 321 yards and two TDs to Adarius Bowman, but was also intercepted twice.
Bowman finished with six catches for 199 yards. Backup quarterback Jonathan Crompton ran in another late score.
Former Lions kicker Hugh O'Neill finished 2 for 2 on field goals as the Eskimos dropped their fifth straight game.
Re-acquired by the Lions last month from the Winnipeg Blue Bombers, Pierce entered the game at the start of the second quarter trailing 12-1 after conceding a safety and went to work after defensive back J.R. Larose picked off Reilly for the first interception of his career.
Logan scored on the very next play, taking a handoff and running right before reversing his field and picking up Pierce's block down the left sideline to make it 12-8.
Reilly hooked up with Bowman on a 45-yard pass to set up a short O'Neill field goal, but Pierce and the Lions' offence found its groove once B.C got the ball back.
The veteran pivot was calm under pressure and marched his team down the field before finding Harris with a shovel pass from eight yards out to tie the score 15-15.
Pierce, who finished 11-of-14 passing for 141 yards, threw his second TD of the night on B.C.'s first possession of the third quarter, hooking up with Arceneaux on a 43-yard strike.
The Lions got the ball back at midfield later in the quarter and were aided by a pass interference call to set up a short TD pass to Harris, his second of the night to make it 29-15.
"We have great playmakers on this team. Our guys, they make plays around you," said Pierce, who also played with the Lions between 2005 and 2009. "As a quarterback in this offence you don't need to win the game. You have to put the ball in the guys' hands and sit back and watch them work."
B.C. defensive back Cord Parks intercepted Reilly in Edmonton territory early in the fourth quarter to set up a Pierce's two-yard plunge.
Reilly led the Eskimos down the field and hooked up with Bowman from 14 yards out for his second TD of the night midway through the quarter.
DeMarco re-entered the game for the Lions as Pierce took a much deserved break late and threw a four-yard pass to Arceneaux for his second TD to make it 43-22. Crompton then dove into the end zone with under a minute to go for Edmonton to round out the scoring.
DeMarco got his sixth straight start in place of injured No. 1 quarterback Travis Lulay, but did nothing for a stagnant Lions offence in the first quarter, completing just 2-of-6 passes for 11 yards.
Lulay has been out since suffering an injury to his throwing shoulder on Sept. 15 against the Montreal Alouettes. He was originally expected to miss just two weeks, but there's still no timetable for his return.
Many in the crowd at B.C. Place Stadium were still getting to their seats when Reilly hit Bowman for a 71-yard touchdown on the first play from scrimmage. O'Neill then kicked in a field goal from 23 yards out later in the quarter to make it 10-0.
The Lions talked all week about using their final two regular season game to get back on track ahead of the playoffs, but their offence was anything but fluid early under DeMarco, with the only first down of the opening quarter coming with less than four minutes to play.
That drive stalled and the Lions were forced to punt, with Paul McCallum booting into the Edmonton end zone for a single point that drew a Bronx cheer from the crowd.
Notes: Logan signed with B.C. last week after four seasons in the NFL. He spent the 2008 campaign with the Lions. ... B.C. hosts Calgary next week, while Edmonton visits Saskatchewan. He rushed for 121 yards to become the Lions' first 100-yard rusher since late July. ... The Lions also defeated the Eskimos in the other two meetings this season, 17-3 in the Alberta capital on July 13 and 31-21 in the return match in Vancouver seven days later. ... The Lions' defence gave up points on the first drive of a game for the first time since Week 1.