DETROIT -- David Purcey has the physical tools to be a solid starter for the Blue Jays. It's the mental side of his craft that Toronto wants the young pitcher to continue to hone as he gets used to life in the rotation.

When discussing Purcey this week, Blue Jays pitching coach Brad Arnsberg stressed that the left-hander needs to maintain his focus, because the starter can be practically unhittable at times. Purcey looked to have heeded Arnsberg's advice on Wednesday night, when he guided Toronto to a 4-3 victory over Detroit at Comerica Park.

"He's got to keep his focus and he's got to be able to throw the ball over the plate," Arnsberg said. "When he's in the zone, he's tough -- he's real tough. They don't see it. They don't like hitting off of him."

The Tigers certainly didn't look like they were having a good time against Purcey, and they probably were grateful for the 49-minute rain delay that chased the 6-foot-5 southpaw from the game after six innings. With Purcey on the hill, Detroit's lineup needed 18 tries before finally recording a hit.

Following Purcey's exit, the Tigers managed some late drama, rallying for three runs in the bottom of the ninth inning. The would-be comeback by Detroit was too little, too late, though, still allowing Purcey's performance to stand out when it was all said and done for the Blue Jays (62-59).

"The kid did just an outstanding job for us," Blue Jays manager Cito Gaston said. "You can see him coming. He still has to work on getting ahead of the hitters a little more often than he did tonight. Even though he got behind, he managed to battle those guys and hold them to two hits."

Purcey sliced his way through the first 17 hitters he faced, creating nine flyouts, striking out four and inducing one groundout along the way. His only blips came in the form of three walks, but Purcey managed to strand the runner each time. After Purcey struck out Edgar Renteria and Brandon Inge to open the fifth inning, the Tigers finally broke through.

It took 11 pitches, but Ramon Santiago lofted an offering from Purcey into shallow right field for Detroit's first hit of the game. The crowd inside the stadium roared with approval, but Purcey avoided the type of lapse in focus he might have experienced in the past, inducing a groundout off the bat of Curtis Granderson to end the inning.

It was the type of turn Arnsberg said he hoped to see from Purcey.

"What I'm really trying to talk David into is expect to go out and throw a shutout," Arnsberg said, "but when you don't, don't let it kill your whole day. I think his ability to focus in and keep his focus is something that we're going to really spend a lot of time on and not have those three or four hitter glitches that can cost you that whole ballgame."

Purcey (2-3) said he's learning to adopt that mentality.

"I knew I had to focus," Purcey said, "especially in the fourth and fifth innings, just to relax. I made an effort to try to slow myself down and not let myself fall into situations where they had a good chance to score.

"I've always been like, 'I can try to throw it by people.' But, at this level you can't really do that. You can surprise hitters here and there, but for the most part, you have to pitch and try to stay in good counts."

On this evening, it was Detroit veteran Kenny Rogers (8-10) who experienced a brief lapse that tilted the game in Toronto's favor. The 43-year-old left-hander issued a walk to Marco Scutaro to open the third inning and then allowed consecutive singles to David Eckstein and Alex Rios to load the bases.

One batter later, Toronto's Vernon Wells launched the first pitch he saw from Rogers deep to left field, where the ball ducked just beyond a leaping Ryan Raburn for a grand slam. That gave the Blue Jays a 4-0 advantage that proved ample to send Purcey to his first victory since July 26.

Of course, the showers that interrupted the game for nearly an hour during the top of the seventh robbed Purcey of an opportunity to log at least another inning. That proved to be a blessing for Detroit (58-62), which tagged relievers Scott Downs and Brandon League for a trio of runs in the final frame.

During the Tigers' late charge, Downs -- one of the top setup men in the American League this season -- tumbled to the ground in front of Detroit's dugout while hurrying to back up home plate. The left-handed reliever sprained his right ankle and is likely headed to the disabled list.

"It could be a costly win for us tonight," Gaston said.