Gremio also took the upper hand in the Gaucho (Rio Grande do Sul) with a 2-0 win over arch-rivals Internacional as Brazil's state championships reach their conclusions.
Atletico Mineiro beat Ipatinga 3-2 in the first leg of the Mineiro (Minas Gerais) championship, while Botafogo won the Carioca (Rio) last weekend beating Brazilian champions Flamengo.
The Brazilian season starts with 27 state championships before the national championship kicks off on May 8.
Santos recovered from a 1-0 half time deficit after Bruno Cesar put Santo Andre ahead with a free-kick. Andre Felipe equalised and Wesley scored twice in eight minutes before Rodriguinho pulled one back for Santo Andre.
At the Beira-Rio stadium in Porto Alegre in the southern state of Rio Grande do Sul, goals from defender Rodrigo and striker Borges broke the resistance of Inter's former Argentina goalkeeper Roberto Abbondanzieri in the final 23 minutes.
Before next weekend's second leg, the two teams turn their attention to other competitions.
Inter meet Argentina's Banfield in the first leg of their Libertadores Cup first knockout round tie while Gremio face Fluminense in the Copa Brasil quarter-finals in midweek.
