Matt Dominguez has been on a hot streak, and Monday, it was the Javelinas who paid the price.

The Marlins' top prospect hit a grand slam and drove in a career-high six runs as Surprise held on to defeat Peoria, 8-7, in the Arizona Fall League

Dominguez, who finished a triple shy of the cycle, put the Saguaros on the board with a two-out double to left field in the first inning. Batting with the bases loaded two innings later, the 22-year-old third baseman launched an opposite-field blast over the right-field wall to give Surprise a 6-0 lead.

"The home run was a fastball over the plate and it just kind of kept going," Dominguez said. "I didn't hit it great. I was just trying get a pitch up in the zone and put a good swing on it. I thought it was going to be a sac fly, but it just kept going."

Dominguez's first-inning two-bagger extended his hitting streak to six games, during which he is 10-for-24. After homering for the first time this fall Friday, the former first-rounder is batting .357 with two homers and 10 RBIs.

"I'm just trying to go with a good approach, staying back, seeing the pitch and using my legs more," he said. "[I'm] trying not to jump at the ball and just let it come to me."

Dominguez had never driven in six runs before, notching five RBIs several times in the Minors, most recently June 2, when he homered in back-to-back innings in New Orleans' 22-7 win over Omaha.

Dominguez earned a late-season promotion to Florida, where he hit .247 with two RBIs in 17 Major League games. The California native is hoping that a strong showing in the desert could pay dividends come March.

"It would be nice to have a good AFL and go into Spring Training with confidence," Dominguez said. "Definitely a good AFL would take me into Spring Training with more confidence."

Christian Bethancourt (Braves) and Tyler Bortnick (Rays) each contributed a solo homer and MLB.com's No. 15 prospect Wil Myers drew three walks and scored twice for the Saguaros.

Braves prospect Sean Gilmartin improved to 2-0 after striking out four and allowing two hits over four scoreless innings.

Mets farmhand Jefry Marte hit a three-run homer for the Javelinas, his second straight game with a long ball. Juan Centeno added a two-run double in the ninth as Peoria tallied four runs in the final frame.