"We just kept adding runs," Frazier said. "I thought our offense did a good job staying in the game, just doing little things -- moving runners over, couple big, timely hits and we just came out on top."
Frazier led off the game and hit the first pitch he saw into right-center for a triple and later scored to give the Desert Dogs an early 1-0 lead.
"I knew Manaea was a good pitcher," Frazier said. "I was looking for a fastball early [because] if you fall behind guys like that it's usually tough to be successful. He threw a fastball right there and I put a good swing on it, luckily it fell."
However, Manaea then found a groove and shut down the Desert Dogs, retiring 10 consecutive batters in the process.
Manaea, the Athletics' No. 3 prospect according to MLBpipeline.com, allowed just one run on two hits in four innings, while striking out four.
"He's just a great pitcher," Frazier said. "He was moving his fastball in and out, up and down. Throw a few off-speeds in there and it's tough to hit a guy like that, who is changing eye levels so much."
With the left-hander on the mound, Mesa built a 4-1 lead -- courtesy of Jeimer Candelario.
The Cubs' No. 19 prospect was in the middle of all of Mesa's offense as he went 3-for-4 with a run scored.
As Candelario was getting on base, a pair of Angels prospects were driving the runs in.
Eric Aguilera went 2-for-4 with a pair of RBIs and Stephen McGee, who hit just two home runs in 68 games this season, blasted a solo shot to left.
However, Mesa was unable to hold onto the lead.
Glendale tied the game with a three-run fifth and then Frazier came through with a go-ahead triple in the seventh.
"I got kind of lucky on the last one," Frazier said. "Cutter got in on me a little bit, but just found a hole. That's baseball, just one of those days I guess. Some days you get those, some days you don't."
Mesa was able to tie the game back up in the seventh, but once again it did not hold as Pirates No. 2 prospect Austin Meadows added an RBI in the eighth and White Sox prospect Nicky Delmonico -- who homered earlier in the game -- drove in the eventual game winner with a sacrifice fly.