The 221 yards the Cincinnati Bengals rushed for against Oakland on Sunday was the team’s highest total since 2004. And that came on the heels of a 189-yard effort in Kansas City, which at the time was club’s most since 2009.

It’s been quite the resurgence for a running game that was plodding along at just 3.7 yards per carry and ranked 25th out of 32 NFL teams two weeks earlier.

“The guys are doing a good job of seeing the look together through the same eyes and coming off the football together in unison,” Bengals head coach Marvin Lewis said. “We just have to keep going and do things correctly. Linemen love to run the football. That gets them excited.”

The newfound success has been a testament to patience as much as anything else. With the exception of rookie Trevor Robinson taking over for Jeff Faine at center four weeks ago, there haven’t been any changes in the personnel or scheme.

The Bengals started the season with a rookie at right guard in Kevin Zeitler and a second-year player with three career starts at left guard in Clint Boling. Mix in the rookie Robinson at center and a starting tailback in BenJarvus Green-Ellis, who is in his first year with the team, and it’s not surprising the offense didn’t hit the ground running.

“It was tough early on,” Zeitler admitted. “But I think everything has clicked. Finally, everyone is getting the job done that they need to, the right reads being made. It’s a lot of fun, I know that. Everyone is just getting it done.”

Green-Ellis ran for 101 yards at Kansas City and 129 against Oakland, marking the first time in his career he’s had back-to-back 100-yard games. He’s also the first Cincinnati back to do it since Cedric Benson in the final two games of 2008.

Cedric Peerman has provided a spark as well, rushing for 136 yards the last two games after gaining just 120 in his first 3 ½ years in the league.

“The line’s doing a good job opening up holes and (quarterback Andy Dalton) is doing a good job getting us in good plays and the right runs, and of course the backs are finishing,” offensive coordinator Jay Gruden said. “Really, in the running game it’s got to be everybody. Everybody’s got to be involved. . It helps to have A.J. (Green) out there where teams are doubling him and taking a safety over there and gives us one less guy to block.”

That was the case Sunday on a third-and-1 play when Green-Ellis burst through the line into a wide-open secondary. The play went for a career-long 48 yards down to the 1, and two plays later Green-Ellis bulled in for the touchdown — his third in the last four games and fifth of the season.

He did it again on a second-and-4 play in the fourth quarter, ripping off a 39-yard run — the second longest of his career — down to the 1.

The Bengals finished with an average of 6.5 yards per carry after logging a 5.0 average the week before against the Chiefs. Their next stop is in San Diego against a Chargers team that ranks fifth in the league against the run, and that will be followed by what figures to be four cold-weather games against the Cowboys, Eagles, Steelers and Ravens.

“Overall, I’ve been very, very pleased the last few weeks with the running game,” Gruden said. “We still have to get better because it’s very important the colder the weather is going to get.”