Willian, 20, has been a much maligned figure at the Morumbi this year after an 11-goal state championship haul was followed by just one goal in Brasileirão action.
In reality, the striker has completed 90 minutes just three times in the league campaign, given the prominence of colleague Luis Fabiano, but it has not stopped the boos ringing out on recent occasions.
However, having been told to earn himself a new contract against La U, Willian José was clinical, latching onto passes from Wellington and Denilson to twice finish in fine style in the opening 20 minutes of the encounter.
“I haven"t been playing much," he explained. “Since the booing I began to train even harder, hoping for my chance and I took it with both hands. I am very happy. Many people speak and criticise me, but I care little.
“I just get on with my job, day-by-day. I know my responsibilities, as back-up for Luis [Fabiano] and I am very grateful that [manager] Ney Franco believes in me. I want to keep improving here."
When Universidad de Chile were reduced to 10-men on the hour mark, as last-man Mena brought down the escaping Osvaldo, it looked like the situation could get worse for the hosts, but the Chileans pulled together to ensure the result became no worse.
São Paulo will, though, be confident of securing a Copa Sudamericana semi-final place as they take a 2-goal cushion into the return leg at the Morumbi.
Universidad de Chile: Herrera; Gonzales, Rojas, Acevedo, Cereceda (Duma 58"); Lorenzetti (Rodriguez 46"), Aranguiz, Gutierrez, Mena; Martinez (Marino 78"), Ubilla. Coach: J. Sampaoli
São Paulo: Rogério Ceni; Douglas, Rafael Tolói, Rhodolfo, Cortez (Maicon 46"); Denílson, Wellington, Jádson (Édson Silva 61"), Lucas Moura; Osvaldo (Ademilson 78"), Willian José. Coach: Ney Franco
