Despite a 116-minute rain delay, Orioles pitcher Brad Bergesen threw well in his major league debut, holding the White Sox to just one earned-run and four hits in five and two thirds innings.
Aubrey Huff began the revelry with a two-run blast in the third inning, the first of his two dingers on the night.
The White Sox scratched back to tie the score at two in the fourth on RBI singles by Jermaine Dye and Paul Konerko.
The Sox took the lead 3-2 on a run scoring ground out by Brian Anderson in the fifth. That lead was short-lived, however, as an RBI double by Nick Markakis, followed by a run-scoring single by Luke Scott put the Orioles ahead for good in the bottom of the fifth.
Contreras got the hook with one out in bottom of the sixth after surrendering another run. Clayton Richard took the bump and promptly gave up an RBI single to Markakis, who ended up four-for-four on the night, making the tally 6-3 in favor of the birds.
The rest was academic.
The White Sox managed only five hits. The main concern is the performance of Contreras, whom the Sox are counting on at the tail end of the rotation.
The good news is that Alexei Ramirez was two-for-four, after having started the season with just five hits in his first 40 at-bats.
Game two of the series is scheduled for Wednesday evening with John Danks slated to face the Orioles Jeremy Guthrie.