Complex sentence: Its critical success revitalized the career of Martin Ritt, who had been blacklisted during most of the 1950s, and also earned national fame for Paul Newman, who won the Best Actor Award at the Cannes Film Festival.
Split into simpler sentences: Its critical success revitalized the career of Ritt, who had been blacklisted during most of the 1950s. Newman won the Best Actor Award at the Cannes Film Festival.