ST. LOUIS – Going into Monday's final round of the U.S. Chess Championship, a grandmaster from Minnetonka is still in the hunt for the national title, but he's going to need all the breaks to go his way.

After he drew his game Sunday, Wesley So remains only a half-point behind the tournament leader. But he now has company in second place after the defending champion won his game to catch up to So.

Even more worrisome for So: He must rely on the lowest-rated, last-place player to trip up the tournament leader in their final-round matchup, a highly unlikely outcome.

Although his hopes of winning the championship appear to be fading, the 22-year-old So has played solidly and at times brilliantly. He has not lost a game in the tournament in St. Louis. With four wins and six draws, he's one of only three players among the 12 to stay undefeated. And this is the strongest field ever to battle for the national title.

So pressed for a much-needed win in Sunday's game against his former college roommate, Ray Robson, whom he usually beat when the two played friendly speed chess games in their student days.

But in their encounter Sunday, after So made his 19th move — following a 20-minute think — Robson countered with a move that caught So off guard.

"I made one mistake," So said of his failure to anticipate Robson's plan.

Robson's move forced So into an exchange of pieces that drained the tension from the board and robbed So of any chance to play for an advantage. Sixteen moves later they agreed to a draw.

Now So and the other player in second place, Hikaru Nakamura, have to put their hopes in the hands of a player who's the least likely to help them out.

That player, 16-year-old Akshat Chandra, needs to hold tournament leader Fabiano Caruana to at least a draw in their final-round game for So and Nakamura to climb into a tie for first place — that is if they can win their respective final games.

But to understand what a mismatch the Caruana-Chandra game will be, consider this: Caruana is ranked third in the world, while Chandra is barely in the top 1,000.

Nakamura doesn't expect Chandra to bail him and So out.

"Basically, I'm assuming Fabiano will take care of business, like he should, tomorrow," Nakamura said.

Caruana said he didn't feel too much pressure from those chasing him.

"I'm relatively confident," he said. "But I know from experience that anything can happen, so I wouldn't say I'm complacent."

So, meanwhile, realizes that he has to win his final game to have even an outside chance of catching Caruana.

His opponent is someone he's played twice before, beating him once and drawing the other game.

"I know his style quite well," So said of Aleksandr Lenderman. "I have a good feeling for what he'll play."

With the final round set to begin at 1 p.m. Monday, three of the tournament's six games — Lenderman-So, Chandra-Caruana, and Robson-Nakamura — could have a bearing on who becomes champion.

Tournament commentator and analyst Jennifer Shahade channeled the rock band The Bangles as she billed the final round as "Manic Monday." That song, incidentally, was written by Prince.

Dennis J. McGrath • 612-673-4293