Halladay, the American League Cy Young Award winner in 2003, has been dominating hitters all season, and has been going deep into almost every game he pitches.
The Toronto right-hander did exactly that on Monday, as he dealt the A's a 6-1 loss at Rogers Centre. With the defeat, Oakland (53-58) has now dropped seven straight games and 14 of 16 since the All-Star break.
With Halladay (13-8) in top form, it seemed like almost an impossible task for the A's to put an end to their losing skid.
"He is one of the best pitchers in the game, it's no doubt," said Oakland manager Bob Geren, following the loss. "He has a little bit of everything that it takes. He has real good command on both sides [of the plate], he has two different fastballs, and even changes his speeds on his curveball.
"He's obviously a very intelligent pitcher," Geren added. "You can see the way he works -- very in command."
The Toronto (56-56) right-hander allowed just one run while scattering four hits over eight innings. He walked one, struck out eight, and induced 10 outs via ground ball.
The lone run for Oakland came in the eighth inning when shortstop Bobby Crosby launched a 2-1 pitch from Halladay into the left-center-field stands for his fifth home run of the season. That hit represented the first time in the game that the A's were able to put a runner past second base.
"He's tough," said A's left fielder Jack Cust, who clubbed a double off Halladay in the fourth inning, but was stranded at second base. "The thing with him though is you know you are going to get a lot of strikes. He throws the ball on the plate and you have to be ready to hit. But tonight, he switched some things up."
Cust was also impressed with the fact that Halladay had all of his pitches working, especially his curveball, which in turn gave the A's fits all night.
"His ball has real good late life on it," Cust said. "And his curveball -- it seems that he throws it different speeds, but really it's the same speed. I don't know how he gets it to looks like that. You look up there [on the radar] and it's the same speed, but [at the plate] it seems like its a little slower, a little sharper.
"He just knows how to pitch."
Including Monday's affair, the A's have hit a collective .215 in the 16 games since the All-Star break. During that span, the club has averaged just 2.8 runs per game.
It doesn't help matters that A's starters have suffered a long string of rough starts since the break. The meagre run support coupled with shaky starting pitching has produced the recipe for Oakland's struggles since the break. Entering the series opener against Toronto, starters were 1-9 with a 6.48 ERA over their last 15 games.
Monday starter Sean Gallagher did not do much to help the cause, lasting just three innings in his start. The Oakland right-hander allowed five runs (four earned) on four hits. He walked and struck out four, exhausting a total of 94 pitches during his brief outing.
In his start, Gallagher (1-1) aided the Jays on a few occasions, helping them to score runs without so much as surrendering hits.
With the bases loaded in the second inning, Gallagher hit Toronto third baseman Marco Scutaro with a pitch, allowing the Jays to open the scoring. An inning later, Gallagher found himself with the bases loaded again, and this time proceeded to plunk Adam Lind to give the Jays a 2-0 lead.
"I think I was trying to nibble way too much," Gallagher said of the bases-loaded situations. "I think I was trying to make two perfect pitches and I ended up missing by a lot most of the time."
In the third inning, following Lind's at-bat, the Jays were able to score a third run when Gallagher served up a passed ball to catcher Kurt Suzuki. After an RBI single by Matt Stairs and a sacrifice fly from Brad Wilkerson, Toronto added two more runs off the A's starter to push its lead to 5-0.
Against Halladay, a deficit like that was extremely hard to overcome.
"When you go against somebody like that, it's always tough," said Geren. "Our offense is struggling and if we fall behind, those are all pretty good obstacles to overcome when you have somebody like that out there."
David Singh is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.