"When you come out of there with beat-up shins, it shows you how much his ball was moving," Mariners manager Don Wakamatsu said. "He was awfully tough."
Ichiro Suzuki fouled a pitch off his right shin and was removed from the game in the eighth inning. He is expected to play Saturday afternoon.
Adrian Beltre fouled a ball off his foot, stuck around until the end, but is doubtful for Saturday.
"It just seemed to get worse and worse as the game went along," Wakamatsu said of Beltre's pain. "I don't foresee him playing tomorrow."
Franklin Gutierrez was another victim, getting hit in the foot with a foul ball and stinging his hands on a broken-bat out.
"Nothing [Halladay] threw was straight," Wakamatsu added. "It's very difficult to square a ball off against him. You never see Ichiro foul a ball off his foot. That just shows how much his ball moves. He had balls breaking both ways."
Through the first half of the game, the Mariners actually had more scoring opportunities against Halladay than the Blue Jays had against Seattle right-hander Doug Fister.
The rookie matched the former American League Cy Young Award winner pitch-for-pitch through the first four innings, and he really had the upper hand. Fister retired the first 13 batters he faced, using an assortment of pitches and speeds to completely contain the Jays.
While Fister was mowing down the Blue Jays in the early innings, the Mariners were putting runners on base against Halladay -- and leaving them on base.
Jose Lopez doubled to right-center with two outs in the first inning and never moved.
Mike Carp doubled down the first-base line with two outs in the second inning and was stranded.
And one-out singles by Ichiro and Gutierrez in the third put runners on first and second before Lopez grounded into an inning-ending double play.
The missed opportunities became even more frustrating when the Jays finally broke through against Fister in the fifth inning, when a single and double put him in trouble. He worked himself out of that jam, but a one-out single to Jose Bautista and ensuing home run by second baseman Aaron Hill in the sixth gave Halladay all the runs he would need to win his 16th game of the season.
Hill's 34th home run of the season was the 12th one Fister has surrendered since being promoted from Triple-A Tacoma nine starts ago.
Of the 28 runs he has allowed while pitching for Seattle, 18 have come via home runs.
"His game is about location," Wakamatsu said. "He does a lot of things right for a young guy, so you know it's in there. He just needs better consistency. He kept a good-hitting ballclub off-balance."
Fister departed with two outs and two runners on base in the seventh inning. A wild pitch thrown by reliever Chris Jakubauskas advanced both runners, and Bautista snuck a grounder through the left side of the infield to drive them in.
"I thought Doug Fister threw a heck of a ballgame," Wakamatsu said. "Giving up two runs through six innings is a pretty good outing. At the tail end there, he started to get hit a little when he left some balls up."
It was only the second shutout this month for the Mariners, who could have clinched a .500 record with a victory, although with eight games remaining, that should not be a problem.
Kenji Johjima, who packed an 0-for-12 skid into the game, doubled in the fourth and seventh innings to lead an offense that was 0-for-6 with runners in scoring position.
The four-game series -- and final road trip of the season -- continues on Saturday afternoon with right-hander Ian Snell taking on the Jays and left-hander David Purcey.