John McDonald prides himself on his defence, but that's exactly what let him down Thursday.

The usually sure-handed McDonald threw high to first base in the ninth to key a two-run inning as the Chicago White Sox downed the Toronto Blue Jays 3-1.

"I practise that play every day," McDonald said. "So I should finish it. I practise it playing fast. I just threw it high."

Former Blue Jay Alex Rios ended up at second on McDonald's error on the throw from third and scored the first of the two runs for the White Sox (24-28) on an infield hit by Juan Pierre. A throwing error by first baseman Juan Rivera on the same play allowed Gordon Beckham to score the second run.

But if McDonald had made the play, Pierre would never have been at the plate.

"Rios got out of the box good, he was going down the line good," Blue Jays manager John Farrell said. "It was going to be a bang-bang play when executed. But as he came through the ball to hurry the throw it sailed high. We've certainly become accustomed to John's outstanding defence but tonight it didn't work that way."

The Blue Jays (24-26) still had a chance to get out of the inning unscathed. A.J. Pierzynski couldn't get the bunt down before striking out, but Rios took third on a wild pitch by left-hander Marc Rzepczynski (2-1). Omar Vizquel struck out before Beckham was hit by a pitch. As the count went to 3-2 on Pierre, Beckham stole second.

After fouling off a pitch to keep the inning alive, Pierre hit a hard grounder to Rivera but Rzepczynski was late covering the bag as Rios scored. Rivera's low throw eluded the pitcher and Beckham scored on the error.

"(Rivera) gave ground to field the ball and time the hop," Farrell said. "By the time Zep got there, even if he catches the ball it's likely(Pierre) beats it out. That's what speed can do. Speed can put pressure on the defence."

Said Pierre: "(Rzepczynski) is pretty nasty on the mound. I just battled and ended up putting the ball where they had to make a great play to get me."

Rzepczynski then allowed a ground-rule double to Alexei Ramirez but Jon Rauch ended the inning on a popup by Carlos Quentin.

Yunel Escobar's fifth home run of the season in the sixth accounted for Toronto's only run.

Toronto native Jesse Crain (2-1) pitched one-third of an inning to pick up the win for the White Sox. Sergio Santos, a former Blue Jay minor-league infielder, pitched the ninth for his eighth save.

Toronto starter Brandon Morrow went seven innings, allowing four hits, two walks and one run while striking out five. He was removed after only 102 pitches and did not figure in the decision.

It was his best outing of the season and he was being caught for the first time in a regular-season game by J.P. Arencibia. It worked well after a couple of first-inning glitches. Jose Molina, who has been catching Morrow, was behind the plate in Wednesday's 7-3 loss in New York. Farrell said he is going to start using him more like a more traditional backup catcher.

"I felt like I was throwing straight downhill the whole game," Morrow said. "I had some better movement on my fastball and keeping it down like that. And when I was missing I was missing down."

Chicago starter Phil Humber allowed six hits, one walk and one run in 7 2-3 innings.

Notes: Attendance at Roger Centre was 14,353. ... Farrell fell short of saying it was going to be closer by committee but what he described sure sounded like it. He said before Thursday's game that factors such as matchups and who has a hot hand could be considered when deciding who could close. Frank Francisco, the current closer, Jon Rauch, who opened the season as closer, Octavio Dotel and possibly Jason Frasor are the ninth-inning options. ... Right-hander Dustin McGowan who has not appeared in a major-league game since 2008 because of shoulder injuries has been pitching at extended spring training regularly for one inning every three or four days. Farrell said the results have been encouraging. ... Right-hander Kyle Drabek (3-3, 4.34 earned-run average) will start Friday for Toronto against Chicago left-hander Mark Buehrle (4-3, 3.92 ERA).