At the start of the Mass, a man shouting "Down with communism" was taken away by security officials. Others in the crowded booed the man for spoiling the atmosphere gucci bags and shouted "Cuba, Cuba, Cuba".
Just three days after saying that communism no longer works in Cuba, the 84-year-old German pope took a softer stance as he began a three-day trip aimed at boosting the Church's role on the island.
Arriving in Santiago de Cuba, he delivered a carefully worded, nuanced and balanced speech that was less direct in criticizing Cuba's one-party system but included some thinly-veiled phrases addressing its human rights record.
"I carry in my heart the just aspirations and legitimate desires of all Cubans, wherever they may be," he said, including the "sufferings" of prisoners and their families, a reference likely to be well received by political dissidents on the island as well as Cuban American exiles in the United States.
Decades of hostility followed Cuba's 1959 revolution but Church-state relations have improved steadily in recent years, helped by Pope John Paul II's landmark visit in 1998.
Benedict called that trip "a gentle breath of fresh air" but said that while great strides had been made, "many areas remain in which greater progress can and ought to be made, especially as regards the indispensable public contribution that religion is called to make in the gucci outlet life of society".
Cuban bishops and the government are still at odds over issues such as Church use of the media and public education, which the Church considers are fundamental to its role as a moral force in society.
Benedict is trying to cement the Church's recent gains here and offer more help in assuring that whatever transition comes is buffered by its social programs, such as care centers for the elderly and limited after-school and adult education programs.
Castro, younger brother of Cuba's revolutionary leader Fidel, warmly greeted the pope at the airport, grasping both of his hands and briefly bowing before him.
The president, who was raised a Catholic, was dressed in a dark suit and was accompanied by a full Honor Guard and artillery gun salute for the pope. When the wind blew Benedict's white vestments around his head, Castro put them back across his shoulders.
He then delivered a firm political lecture about the injustices of U.S. hostility toward Cuba, including a 50-year-old economic embargo, and the island's "tenacious resistance" to preserve its independence and "follow its own path."
Castro has steadily improved relations with the Church using it as an interlocutor on issues such as political prisoners and dissidents, while moving forward with reforms to Cuba's struggling Soviet-style economy.
They include slashing a million government jobs and freeing up some sectors to small-scale private enterprise. The Church has urged Castro to move farther and faster to modernize Cuba, both economically and politically.
Benedict fired an unexpected salvo on Friday when he gucci shirts told reporters on his plane that communism in Cuba had failed and a new economic model was needed, adding that the Church was willing to offer its help "to avoid traumas."
The Cuban government offered a diplomatic response to the Pope's criticism, saying that Cuba would "listen with all respect" to the Pope and welcomed "the exchange of ideas."
In what appeared to be an effort to balance his remarks, Benedict made an apparent dig at capitalist greed on Monday, blaming the global economic crisis on "the ambition and selfishness of certain powers which take little account of the true good of individuals and families."
Cuba is going through a key moment in its history, Benedict said, hinting that with the advancing age of the Castro brothers the island was "already looking to the future."
Church officials say Benedict's schedule in Cuba has not allowed for meetings with dissidents, who say Castro's government flouts human rights and suppresses their voices.
The dissident movement Damas de Blanco, or Ladies in White, a group of Catholic women that campaigns for the release of political prisoners, said it had been told by Cuban authorities to keep clear of the pope's Mass in Santiago.
"They are going to present the pope with a facade, not with the true Cuba," said Ana Celia Rodriguez, a 42-year-old mother of three who is planning to try to attend black gucci belt anyway.