The Rockies' No. 4 prospect struck out five and gave up five hits over 7 1/3 innings Friday night as Modesto blanked San Jose, 2-0, to advance to the California League semifinals.
Matzek (1-0) walked one and faced only five batters over the minimum. All five hits were singles and the 21-year-old left-hander did not allow a runner to advance past second base.
"He was extremely composed, he had a good rhythm out there," Nuts manager Lenn Sakata said. "He was going right after them, which is what you need to do. He gave us what we needed in a crucial situation. It was probably one of his two or three best starts all year. The timing was right."
"Somebody has to step up and it has to be a starting pitcher. He did what he needed to do to give us a chance. There weren't very many balls hit hard, it's a helluva effort."
For Sakata, the win was sweet for a couple of reasons. It came against a team he managed for six seasons and guided to three Cal League championships. And the Giants are considered by many to be the class of the league.
"I'm not gonna lie to you, it was extremely gratifying to beat them, my former employer," he said. "They're kind of like the Yankees of this league -- huge resources, biggest city in the league. To beat them is a huge accomplishment. The atmosphere of that ballpark, they're classy, they have nice uniforms, it's a different feeling when you play the Giants."
After losing the series opener and rallying to win Game 2, the Nuts jumped out a 1-0 lead in the first inning on Jared Clark's RBI single.
"Our club plays better when we score first, it gives us momentum and confidence," said Sakata, a former big league infielder. "Tonight was a good way to start the game off. We executed enough to keep the lead, and it was a hard-fought game."
Isaiah Froneberger retired all four batters he faced and Adam Jorgensen retired Adam Duvall on a fly ball to right field for his second postseason save.
Modesto heads to Bakersfield to open the best-of-5 North Division finals on Saturday.
"The kids are very excited to advance, everybody wants to keep playing," Sakata said. "This time of the year, staying focused is the hardest thing. This group is still into playing baseball, which is very, very good."
Giants starter Taylor Rogers (0-1) struck out five and allowed two runs on six hits over five innings.
In other California League playoff action:
Lancaster 3, Lake Elsinore 2
David Martinez allowed a run on six hits over six innings as the JetHawks advanced to the South Division finals.
Domingo Santana drove in a pair of runs and Jorge De Leon got Tommy Medica to pop out with the bases loaded in the ninth inning to end the game.
Donavan Tate drove in a run for the Storm. Box score