PHOTO BY NEWMAN LOWRANCE/ST. LOUIS RAMS Rams’ rookie quarterback Keith Null started his third consecutive game Sunday, completing 20 passes for 171 yards and a touchdown. While his team continues to struggle, rookie quarterback Keith Null, of Lampasas, is finding his rhythm.

St. Louis’ sixth-round draft pick Null started for a third consecutive game Sunday at Arizona and, for the third consecutive time, his Rams (1-14) lost.

After holding Arizona (10-5) scoreless through the first quarter, the Cardinals exploded for 17 points before halftime and never looked back, winning by 21 points, 31-10.

The Rams were playing without the NFL’s second-leading rusher

Steven Jackson who was suffering from a sore lower back.

season nears,

With 10:43 remaining in the third quarter, Null engineered the team’s lone touchdown-producing drive, connecting with Brandon Gibson for a 21-yard score to cut the deficit to 10 points at 17-7.

The pass was originally ruled incomplete, but was overturned after an official’s review determined his knee landed in the end zone.

“[That was] very nice,” Rams head coach Steve Spagnuolo told the team’s official website. “I give credit to the coaches upstairs too. They saw it was a foot and a knee and he came up with it. It was nice to see Brandon get that.”

Null finished the day with a solid 171 passing yards on 20 of 31 attempts but also threw three interceptions and his offensive line allowed four sacks.

Despite completing 64.7 percent of his passes (66 of 102) in his short career, Null has thrown nine picks and has been sacked eight times.

St. Louis wraps up its season Sunday against the 49ers (7-8).