Updated

By Laird Harrison

SAN FRANCISCO (Reuters) - Federal prosecutors dropped one of five charges against Barry Bonds on Wednesday as the baseball home run king's lawyers rested their case without calling any witnesses.

Bonds has pleaded not guilty to perjury charges stemming from his denial to a grand jury in 2003 that he had ever knowingly taken performance-enhancing drugs.

The attorneys for both sides said they would give their closing arguments on Thursday, followed by jury deliberations in the case, one of the last strands of a probe into steroid use in professional sports that stunned the nation.

Bonds entered the court smiling on Wednesday, pausing to greet friends and family in the front row before taking his seat with his attorneys.

Government prosecutors had filed four charges that he lied to a grand jury pegged to four specific statements, as well as an obstruction of justice charge.

On Wednesday, the prosecution bowed to an argument by Bonds' attorneys that there was no evidence for one of the charges against the slugger -- that Bonds lied when he said he never "took anything" from his personal trainer prior to the 2003 baseball season.

"No, no, no, not at all," Bonds told the grand jury. "Not at all."

Based on the context, Bonds' answer could be narrowly understood to mean that he never took the "clear" and the "cream," a specific preparation of drugs meant to increase an athlete's testosterone in a way that could not be detected.

But the prosecution never presented evidence that Bonds used that specific drug before the 2003 season started, defense attorney Dennis Riordan argued.

Or Bonds' answer could be broadly understood to mean that Bonds never took any substance at all from his trainer -- even a hot dog, Riordan pointed out. In that case, U.S. District Judge Susan Illston said, the answer is so vague as to be meaningless.

Bonds hit 762 home runs, more than any other player in the history of Major League Baseball. While playing for the San Francisco Giants, Bonds broke Hank Aaron's 33-year-old career home run record in August 2007.

Three months later, a grand jury indicted him on charges of perjury and obstruction of justice.

Bonds told the grand jury he did not knowingly use steroids or human growth hormone and said he never questioned the flaxseed oil, vitamins, protein shakes and creams his trainer supplied him.

The prosecution's decision to drop this charge leaves four others. The first three are charges of giving "false statements." First, he said, "not that I know of" when asked if he took steroids. Second, he said, "No, no," when asked if anyone had given him an injection other than a physician. Third, he said, "No," when asked if his trainer ever gave him anything he understood to be a human growth hormone.

The fourth remaining charge is "obstruction of justice."

The case in U.S. District Court, Northern District of California is United States of America v. Barry Lamar Bonds, 07-cr-732.

(Editing by Peter Henderson and Eric Walsh)