Unatego’s Kellen Komenda answered with a two-run homer to left in the bottom of the inning to pull Unatego to 4-3.
But in the third inning, Kolvic hit a three-run double to increase UV’s advantage to 7-3.
Ryan Postma went 2-for-4 and scored twice for UV.
Unatego (9-7, 7-4) will travel to Hancock on Monday for a MAC semifinal.
Windham 6, Davenport 3
Winning pitcher Anthony Savasta had three hits and two RBIs to lead visiting Windham in the Delaware League.
Savasta pitched the final five innings, allowing two runs on three hits. He struck out five and walked none.
Leading, 3-2, in the fifth inning, Aidan Cohane hit an RBI double and Savasta contributed an RBI single as the Warriors took a 5-2 lead.
Chris Kopf and Kyle Wamsley each went 2-for-3 with a double for Davenport (6-4, 4-4), which will host Stamford in a non-league game at 1 p.m. Saturday.
Windham is at Downsville on Friday.
Edmeston 19, Worcester 0
West Division champion Edmeston had 15 hits during a Tri-Valley League victory shortened to five innings because of the 15-run rule.
Winning pitcher Bryan Head struck out seven and walked one over four innings.
Josh Nicolosi hit a two-run double during the Panthers’ eight-run first inning.
Mike Clark and Dylan Rollins had three hits and three RBIs apiece, and Lucas Miller finished with two hits and two RBIs for Edmeston (11-1, 10-0), which will host Morris today.
Roxbury 25, H-T 18
Trailing, 14-12, host Roxbury scored 10 times in the fifth inning en route to a Delaware League victory.
Jacob Davis hit a three-run triple in the fifth and finished 4-for-6 with seven RBIs for the Rockets. Will Rendler had two hits and three RBIs, and Beau O’Donnell scored five times for Roxbury (3-8, 3-4), which will travel to Margaretville on Friday.
Elijah Ruoff went 3-for-6 with four RBIs, Dylan Legg went 2-for-4 with three RBIs and Zac Hommel drove in four runs for Hunter-Tannersville.