Baseball fans can be impatient when it comes to young prospects, expecting them to produce right away.

Portland Sea Dogs outfielder Manuel Margot made his Hadlock Field debut Saturday night. Only 20, Margot waited until the sixth inning to grab attention.

Margot swatted a three-run homer in the sixth inning, a blast that hit the top of the message board in left field.

But Margot was overshadowed by Reading Fightin Phils outfielder Brian Pointer. He hit home runs off three Sea Dogs pitchers to lead Reading to an 8-5 win before a crowd of 6,875.

Pointer, 23 and in his sixth year of pro ball, recorded five RBI. His two-run blast off Miguel Celestino (0-2) in the eighth inning gave the Phils a 6-5 lead.

Celestino, recently sent down from Triple-A Pawtucket, gave up two more runs as Reading improved to 39-35. Portland dropped to 27-48.

Margot, considered one of Boston’s top prospects (ranked No. 7 according to Baseball America), was promoted to Double-A on Monday. He and fellow prospect Sam Travis made their first appearance in Portland on Saturday.

Also showing up was Boston Red Sox catcher Ryan Hanigan, making a rehab appearance as he comes back from a fractured right hand. Hanigan, currently on the 60-day disabled list, caught all nine innings and made four plate appearances, going 0 for 2 with two walks.

Margot finished 1 for 4. Travis, a first baseman, was 0 for 2 with a sacrifice fly and a walk.

But the spotlight belonged to Pointer, a 28th-round draft pick out of high school in 2010. He slowly has made his way through the Phillies’ system, showing power last year with 15 home runs in the pitcher-friendly Florida State League.

Pointer’s three blasts Saturday give him eight homers this season.

In the second inning, Pointer hit a solo shot off Portland starter Heri Quevedo, giving Reading a 2-0 lead.

The Sea Dogs got one run in the second inning. Jantzen Witte doubled, reached third on an error and scored on Travis’ sacrifice fly. In the third, Cole Sturgeon singled and eventually scored on a double play to tie the game.

But Pointer went deep against Michael McCarthy for a two-run homer and a 4-2 lead in the sixth.

Witte singled in the bottom of the sixth. Travis followed with a walk and then Margot smacked a full-count offering from Jesse Biddle, putting Portland ahead 5-4.

In the eighth, Celestino gave up a lead-off walk before Pointer clocked a 95 mph fastball to center field as Reading retook the lead for good.

NOTES: Sea Dogs reliever Jorge Marban pitched 1 2/3 scoreless innings with three strikeouts. He lowered his ERA to 0.52. … Kelly Olynyk of the Boston Celtics made an appearance, throwing out the first pitch and signing autographs. … Sunday’s game is scheduled for 1 p.m., although the weather forecast looks threatening. If rained out, Reading and Portland would play a doubleheader Monday.