Las Vegas - Casino billionaire and GOP super-donor Sheldon Adelson made a rare public appearance Thursday as the lead witness against a Hong Kong businessman who is suing his company for $328 million.

Adelson blazed a trail of casino riches in Asia after doing the same thing in Sin City as CEO of Las Vegas Sands. In recent years, a series of former business associates have sued Sands for a portion of the soaring profits from the Chinese gambling enclave of Macau.

One such businessman, Richard Suen, claims he made it possible for the casino company to win a license in Macau by arranging meetings between executives and Beijing officials in 2001. Sands lawyers say those meetings didn't help, because licenses are distributed by official in Macau, not on the mainland.

Adelson arrived at the Las Vegas courthouse wearing a navy suit, blue tie and white shirt with his initials, SJA, embroidered on the cuff. The longtime supporter of Israel and the Republican Party made headlines last year when he became the biggest donor in political history, contributing with his wife nearly $100 million to help GOP candidates.

His wife, Miriam, led him into the courtroom, but he approached the witness stand using a marble-handled cane. Adelson has a condition known as peripheral neuropathy, and Suen's legal team had said he shouldn't be escorted to the stand, as his wife did in a previous trial, because it would evoke undue sympathy among the jury.

Sands' lawyers have sought to limit media access to the mogul's testimony. The team brought in Harvard professor Alan Dershowitz, a renowned advocate for open court proceedings, to help argue that press photos of Adelson's day in court could threaten the 79-year-old billionaire's security. That argument was overruled.

The legal fight has played out in court once before. In 2008, a jury awarded $58.6 million to Suen, but the Nevada Supreme Court overturned the verdict in 2010. That court said the district judge shouldn't have allowed hearsay statements during the trial, and should have told the jury to assume Chinese officials were following local laws.

Five years later, Adelson has become a better-known figure, and his company has become more profitable. Buoyed in large part by his successes in Macau, Adelson has become the ninth-richest person in America, worth an estimated $26.5 billion, according to Forbes.

Suen, a former business partner of Adelson's brother, now seeks more than three times the amount he requested in 2008 because of Sands' success in Macau. He said he and his company were promised a $5 million success fee and 2 percent of net casino profits in exchange for helping Sands open its first casino in Macau, currently the world's biggest gambling market.

The case hinges on the role that personal relationships and favors play in Chinese culture.

Suen's team argues that Sands needed a fixer's help to cultivate "guanxi" or personal influence. Among other things, Suen says the company won favor during a meeting he arranged by reassuring Beijing Mayor Liu Qi that Congress would not vote on a nonbinding resolution that would have asked the U.S. Olympic Committee to vote against China's bid to host the 2008 in Beijing.

The casino argues that Suen is demanding a success fee for setting up a single 40-minute meeting. They say he had no influential relationship aside from the one with Adelson's brother Leonard, which was the only reason the mogul agreed to meet with him.