In what could become the last big challenge of his brilliant career, Juan Manuel Marquez seeks that elusive convincing victory over Manny Pacquiao on Saturday night at the MGM Grand Arena in Las Vegas (HBO PPV, 9 ET).

It will be the fourth battle in an electrifying series, in which the Mexican fighter has always fallen short in the eyes of the judges. For almost five months, Marquez has worked diligently to improve his conditioning for this bout and his confidence seems as high as ever.

Here are five keys for Marquez against Pacquiao:

Give, don't receive

Low expectation

Over the counter

In the corner we trust

Far from the floor

Bernardo Pilatti is a contributor to ESPNdeportes.com.