SAN FRANCISCO – The outcome was about as satisfying as kissing a frog, smooching a sibling, planting a big, wet one on the neighbor's newborn.

The 49ers had chances Sunday to outlast those slicksters from St. Louis – two perfectly executed fake punts? – but only managed a 24-24 tie in the overtime marathon and left Candlestick Park wondering and worrying about the condition of concussed starting quarterback Alex Smith.

A missed field goal here. A killer penalty there. A stingy defense that relinquished a surprising 458 yards. This was almost a dramatic, sudden-death victory and an exhilarating coming out party for second-year quarterback Colin Kaepernick. The tie goes to the runner, right?

That didn't happen, either. Rushed into the game in the second quarter after Smith complained of blurry vision, Kaepernick completed 11 of 17 passes for 117 yards and ran for a seven-yard touchdown. He kept the Rams on edge most of the afternoon, scrambling when he couldn't find receivers, darting around on designed plays, providing a dynamic dimension that makes him an intriguing prospect – and one the visitors never expected to see.

"If I had to grade Colin, I'd give him a B-plus," tight end Vernon Davis said. "I think he went out there and did a spectacular job. He made plays. He was on. He wanted to show everybody he could do it."

But before a quarterback controversy fully revives, and that Smith vs. Kaepernick conversation spills over the water cooler, it's probably wise to remember that the 49ers didn't win the game. There is still plenty to be said for veteran experience and for the benefits of affording Kaepernick the time and opportunity to observe, listen and learn.

Besides all that, Smith is in the midst of a career season and was coming off one of his most prolific performances. In the 49ers' last game, Oct. 29 at Arizona, he completed 18 of 19 passes for 232 yards and three touchdowns. He was his efficient, cautious, mistake-free self. He was true to form early Sunday against the Rams as well, converting 7 of 8 passes for 72 yards and a touchdown.

True, Smith will never be Drew Brees, but he's a hard guy to take down. He somehow squeezed out the necessary yard for a first down after being slammed by 6-foot-6, 295-pound tackle Kendall Langford, then connected with Michael Crabtree for 19 yards and the 14-yard catch-and-run score that brought the 49ers within 14-7.

A few minutes later, after the Rams went three-and-out, it became apparent something was amiss. Instead of joining the offense back on the field, Smith approached coach Jim Harbaugh and complained of "blurry vision." While the two were talking, Kaepernick threw hurried warmup tosses a few feet away, then quickly entered the game.

Smith, who earlier absorbed a blow to the shoulder/neck area by Rams linebacker Jo-Lonn Dunbar, was led to the bench and examined by team trainers and physicians, who diagnosed him with a concussion. He will undergo further testing in the next few days, per the NFL's increasingly tightening guidelines.

Though he also seemed a little dazed and confused afterward – and he's not a touchy-feely guy to begin with – Harbaugh struggled to characterize his emotions after the altogether dissatisfying ending. Smooching a sibling? Kissing a frog? Welcoming the neighbor's newborn with a big, wet one?

Let's just say Harbaugh was more definitive about the Smith's loss (it hurts) and Kaepernick's gradual effectiveness. His two fumbles, for instance, both occurred on his opening drive. As the clubs swapped wild and crazy plays, appearing on the verge of victory only to commit costly mistakes, the rangy Kaepernick, who has a cannon for an arm, particularly befuddled the Rams with his feet.

He rolled left, he rolled right. He was poised, patient and often maddeningly unpredictable. His critical scamper around the right end for 14 yards helped set up a potential game-winning field goal by David Akers.

"Our offensive line did a great job protecting and opened up the running lanes, so I just tried to take advantage of that," Kaepernick said. "(But) obviously, you don't want a game to end in a tie. I've never been part of one. It's a different feeling."

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