A difficult opening game for the five-time winners of the Copa Libertadores in the opening game of group seven in La Paz, Bolivia on Wednesday night. Boca Juniors, who triumphed in South America's most prestigious club tournament in 1977, 1978, 2000, 2001 and 2003, and their loyal band of fans had travelled to the Hernando Siles Stadium - always a difficult venue at 3,600 metres above sea level. However, the Argentinians dominated the opening exchanges and should have taken the lead after 27 minutes - Neri Cardozo releasing Rodrigo Palacio with a fine throughball that split the Bolivar defence but he wasted the opportunity with a woeful finish as he sliced the ball wide of goal. Then, on the stroke of half-time, Bolivar thought they had made the all-important breakthrough. From a free-kick - Julio Cesar Baldivieso's pinpoint cross was met at the far post by Carlos Saucedo and his header back across goal was nodded into the empty net by Luis Silliero. However, he was correctly flagged for offside and the goal was disallowed. The second half was a fairly turgid affair in very wet conditions but Boca should have made the breakthrough just three minutes after the interval. Martin Palermo won a header and flicked the long ball into the path of Palacio and when his drive was bravely blocked by Joel Zayas, Cardozo somehow blasted the ball wide of an open goal. But that miss looked unlucky when compared with this one - from a Bolivar goal-kick, Saucedo's flick-on was headed into the path of Silliero who shot so tamely wide from a great position after 57 minutes that even he looked bewildered. Shocking finishing all round - points shared.