Hillary Rodham Clinton won a lopsided, but largely symbolic victory Sunday in Puerto Rico's presidential primary, the final act in a weekend of tumult that pushed Barack Obama tantalizingly close to the US Democratic presidential nomination.

The former first lady was winning roughly two-thirds of the votes.

In defeat, Obama was on track to gain at least 14 delegates, bringing him within 50 of the 2,118 needed for the nomination.

US Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y., chats with supporters at the Kaslata Bakery in San Juan, as she campaigns on primary day in Puerto Rico, Sunday, June 1, 2008. [Agencies]

Aides predicted he could clinch the nomination as early as this week, when Montana and South Dakota close out the primary season, and he said he was confident the party would unite for the fall campaign.

"First of all, Senator Clinton is an outstanding public servant, she has worked tirelessly during this campaign ... and she is going to be a great asset when we go into November," he told an audience in Mitchell, S.D. "Whatever differences Senator Clinton and I may have, those differences pale in comparison to the other side."