Alone atop the CFL standings, Saskatchewan Roughriders head coach Corey Chamblin is tuning out the skeptics.

Tristan Jackson returned a missed field goal 129 yards early in the fourth quarter as the Roughriders beat the B.C. Lions 23-20 at Mosaic Stadium on Saturday afternoon to become the league's only unbeaten team.

The Roughriders finished 5-13 in 2011 and were widely written off ahead of this season. But after Saturday's win, Chamblin took some shots at the critics.

"There were excuses why we beat Hamilton, there were excuses why we beat Edmonton and somebody will find excuses why we beat B.C.," said Chamblin. "Like I told the guys, no one gives us anything, we earned it."

The game's turning point came when Jackson scooped up the ball in the Roughriders' end zone following a missed 44-yard field goal attempt by B.C.'s Paul McCallum and returned it to put Saskatchewan ahead 23-13.

After the game, Jackson said the play nearly didn't happen.

"When I caught it, I was going to take a knee," said Jackson, who explained that he decided to run the ball out after seeing a favourable blocking formation ahead of him. "I always believe in my guys in front."

It was a lead the Riders would not relinquish despite a last-gasp B.C. touchdown on an eight-yard pass from quarterback Travis Lulay to wide receiver Marco Iannuzzi.

Jackson's spectacular return was his second of the game.

A crowd of 32,080 watched the early-season showdown of West Division rivals as the Roughriders dropped the defending Grey Cup champion Lions to 2-1 and improved their own record to 3-0.

Midway through the third quarter, with the score tied 13-13, McCallum missed the target on a field goal attempt of 44 yards and Jackson returned to midfield.

Saskatchewan's subsequent drive stalled, despite a penalty against the Lions for illegal contact, and the Roughriders were forced to settle for a 33-yard field goal by Chris Milo.

Expected by some to be a duel between Lulay and Saskatchewan quarterback Darian Durant, the game instead was dominated by two outstanding defences and developed into a battle for field position before Jackson almost single-handedly determined the outcome.

Lulay threw for 345 yards with two touchdowns and two interceptions but the Lions offence put up its lowest scoring total of the season. After two straight home games in Vancouver, Lulay said his team struggled with the noise inside Mosaic Stadium.

"It was a sour first road test, I think that got to us just a little bit," he said. "There was a handful of time we had a little bit of confusion on the offensive side of the ball."

The Lions had opened the scoring on their first possession of the game with a 38-yard field goal by McCallum. The Roughriders responded immediately, with Milo hitting on a field goal of his own from 32 yards out.

The Lions stunned Saskatchewan's revamped defence late in the first quarter when Lulay found wide receiver Kierrie Johnson on a 69-yard pass-and-run touchdown.

A pivotal moment for the Roughriders came midway through the second quarter when Lulay was sacked by defensive tackle Keith Shologan and then intercepted by safety Craig Butler, who returned the pick 19 yards to the B.C. 32.

Following a pass interference penalty against the Lions in the end zone, tailback Kory Sheets found paydirt for Saskatchewan from a yard out.

The victory gives Saskatchewan sole possession of first place in the West Division and could go a long way in establishing the Roughriders' credibility as a legitimate contender.

Saskatchewan fans also had reason to rejoice before the game.

In a ceremony conducted at midfield prior to the opening kickoff, Roughriders CEO Jim Hopson was joined by Regina mayor Pat Fiacco and Saskatchewan premier Brad Wall, who made the official announcement that construction will begin in 2013 on a 33,000-seat open-air stadium that is expected to be completed in time for the 2017 season.