Unfortunately, the total effort only lasted five innings, and Mazzaro left trailing by three runs. Fortunately for the A's, they were able to rally for three runs in the seventh and another in the eighth to defeat the Angles, 4-3, before 43,011 at Angel Stadium.
Mazzaro, who started off his Major League career with two straight wins that covered 13 2/3 scoreless innings, began Saturday night's outing in the same fashion, hitting the corners for strikes and retiring seven of the first eight batters.
In the third and fourth innings, Mazzaro seemed more like the pitcher who lost eight straight after his brilliant first two starts.
In the third, he gave up back-to-back singles and a Bobby Abreu sacrifice fly, giving the Angels a 1-0 lead. In the next inning, Mazzaro struggled even more, giving up a two-run homer to Maicer Izturis and then loading the bases with a wild pitch on a strikeout, a single and a walk before recording the third out.
The fifth inning represented where he is now, as he showed more of what the A's hope to see in the future. Mazzaro easily made it through the frame, giving up only one harmless single.
"I really wanted to come out for the sixth," Mazzaro said. "I was feeling pretty good and had had a short inning."
With 99 pitches in the book, including 66 strikes, and almost 150 innings for the season, Oakland manager Bob Geren decided Mazzaro had done enough.
"He pitched very well. All the young kids have pitched well," Geren said. "They're going to give us as many innings as they can, but we're going to be watching it."
As for the difficulties in the middle of Mazzaro's outing, Geren felt they were typical of those experienced by young pitchers.
"I thought he was just right off the zone, didn't miss by much," the skipper added. "When you go through the lineup a second time, third time, they've had a good look at you. It's a bit harder."
Mazzaro agreed with Geren's assessment.
"I was missing a little bit, probably trying to nibble too much," the 22-year-old right-hander said.
As for the total workload he's experiencing as he moves his way to the end of his first Major League season, Mazzaro doesn't expect any problems.
"I'm getting a little tired as the season goes on," he said. "I've pitched more than I have [previously], but I feel good."
Geren will continuously evaluate his young pitchers and how deep they should go into games.
"With the innings, there are going to be more games where we just ask for five innings from the starters," Geren said. "That's where the performance by Jeff Gray was important. When you put in a guy like Gray in the middle innings and he holds them, that's big."
For Mazzaro and the rest of the young pitching corps, it's all a learning experience. This year also has been a bonding experience for what might well be the next great Oakland staff.
On most staffs, a rookie can go to one of the veterans for advice, but on the A's, it's been communal learning.
"We go to each other; we learn from each other," Mazzaro explained. "We talk after each start about what we did wrong, mistakes ... and about changes that we need to make."
Mazzaro also credits A's coaches, including pitching coach Curt Young, who Mazzaro said teaches them all a lot.
On the other hand, most rookies have to withstand the comparison to the veteran stars on their staff, almost always a daunting task for the new kid on the block. With everyone being new, the comparisons are easier.
"It's probably easier going through this where we're all in the same boat," admitted Mazzaro. "You don't have to compare yourself to guys who have been doing it for years."
The only comparisons Mazzaro and his teammates are subject to is where they are now, compared to where they were in the spring.
As closer Andrew Bailey summed it up, "We've all come a long way."
Glenn Rabney is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.