It's hard to imagine Shaquille O'Neal struggling against any one player in the NBA. Shaq is often considered the most dominant player in NBA history. And he earned that title because, on his day, no one could stop O'Neal from doing what he wanted.
Shaq entered the league in 1992 and immediately became a sensation. Within just 3 seasons, Shaq was able to lead the Orlando Magic to the NBA Finals, and he even beat Michael Jordan and the Chicago Bulls in order to do it.
While his first NBA Finals tryst was too much for him too early, Shaq still dominated during the series, on the scoreboard, and on the glass. In 1996, O'Neal went to the Los Angeles Lakers, and his true dominance was on full display for the world to see.
Within 4 years, Shaq and the Lakers would reach the NBA Finals, where they would dominate and beat the Indiana Pacers, and O'Neal would win his first Finals MVP. The Lakers went on to win the next 2 NBA championships as well, and Shaq was the dominant force behind those title wins.
But even Shaq struggled against one particular opponent. In a past interview, Shaq named Bryant 'Big Country' Reeves as his toughest opponent. He explained how Reeves had a terrible jump shot that he was always able to make, and Shaq would never be able to stop him and would fall behind him on several occasions.
“Big Country would be 15 feet away and I would have to rotate back. He had the ugliest, Duckworth one-handed jumper. He’d shoot it and it would always go in. So at halftime I’m looking at the stats: Shaq 15 [points], Big Country 26.”
While 'Big Country' seemingly got the better of O'Neal, the Lakers would always beat Reeves and the Grizzlies. During the 2000s, the Lakers were the best team in the NBA by some distance.
As O'Neal started to age, his dominance started to wither slightly. But he was still able to put up numbers that most bigs in the NBA would be proud of. At his peak, no one could get the better of O'Neal.