The Cubs infield prospect went 4-for-5 with three RBIs and a stolen base Saturday afternoon to lead the Mesa Solar Sox to a 9-2 victory over the first-place Salt River Rafters.
"Junior had a great day," Mesa manager Joe McEwing said. "He has been playing well for us all season and it shows you how talented he really is. He drives the ball in the gaps, steals bases and puts pressure on the defense. He does all of the little things, and that makes him fun to watch."
Lake, signed in 2008 as an undrafted free agent, plated Robbie Grossman with a one-out single in the first inning, then drove home the Pirates outfield prospect again in the second with a two-out base hit. In the fourth, Lake's double scored White Sox infielder Tyler Saladino from first base. He led off the eighth with another single.
The 21-year-old extended his hitting streak to nine games and has driven in a run in six of his last seven contests.
"Day to day, he brings a lot of energy and he has an understanding of his job, whether he's at third base, shortstop or DH," McEwing said. "All the tools he has are coming into play, whether that's a strong throw or driving the ball over the center-field wall.
"He can change the game every day and he's loaded with potential; it's still untapped. He's a young kid and he has room to grow."
Lake is coming off a summer in which he batted .278 with 12 homers, 51 RBIs and 38 steals in 116 games between Class A Advanced Daytona and Double-A Tennessee.
Grossman went 2-for-2 with a pair of walks, two RBIs and three runs scored out of the leadoff spot for Mesa, which improved to 8-9. He ranks fourth in the league with a .481 on-base percentage. Saladino, a 2010 seventh-round pick, reached base three times, plated three runs and scored twice.
"They grind out every single at-bat," McEwing said of Grossman and Saladino. "They don't give away at-bats, they work the pitchers and they both came up with big hits again today. The way they go about their business is very professional."
The run support from the top of the lineup proved more than enough for Mesa starter Terry Doyle (White Sox), who turned in another strong outing.
Making his fourth AFL start, the Boston College product yielded one hit and two walks while striking out four batters over four scoreless innings. He has given up only two runs -- both on solo homers -- over 16 2/3 innings.
"Terry Doyle is a guy that competes hard, works quickly and keeps the defense on their feet," sMcEwing said. "Just two hits in his last three starts, he's pitching very well. He pounds the zone and lets his defense work."
Catcher Gorman Erickson (Dodgers) was 2-for-4 with a double and two RBIs for Salt River after going 10 games without driving in a run.
Fellow Dodgers prospect Stephen Fife allowed four runs -- one earned -- on three hits and three walks over two innings.
Ashley Marshall is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.