Jonas struck with a stoppage-time header to end 90 minutes of frustration for Benfica as they beat an ultra-cautious Zenit St Petersburg 1-0 at home in the first leg of their Champions League last-16 tie on Tuesday.
Nicolas Gaitan floated a free kick into the area and the Brazilian rose to break the deadlock. Zenit defender Domenico Criscito had been sent off for a second yellow card for the foul which led to the free kick.
The first half had been an unsightly slog with 16 fouls, seven offsides and four bookings.
Benfica came to life in the second half but still struggled to create chances against a tightly-packed, well-drilled Zenit, who were playing their first competitive match since December 9.