The Pirates, whose once-bright season fell apart over the last two months, were officially eliminated from playoff contention.
Tejada delivered RBI singles in both the fourth and sixth innings to complete the scoring.
Jeremy Hefner (3-7) gave up three hits and equaled a career best with seven strikeouts to get the win. In his previous start Hefner did not retire a batter while giving up seven runs to Philadelphia.
Jeff Locke (0-3) was charged with the loss after surrendering five runs on nine hits in 3 2/3.
Beginning in mid-May Pittsburgh went on a 45-26 run that put the Pirates in position for what would have been their first winning season in 20 years. Pittsburgh will have to capture six of its last seven games to have a winning mark.