The top of the 5A baseball rankings is getting crowded.

Grandview, for now, at least, is holding onto the top seed in the CHSAA Class 5A Selection and Seeding Index, which will determine the 32-team regional postseason field in two weeks.

But the Wolves, winners of seven straight, have plenty of challengers in pursuit of the top seed — including No. 2 Mountain Vista, which has won 10 in a row, as well as defending champ Cherry Creek, which has the longest win streak in the classification at 13.

In this week’s look-in on big-school baseball, we’ll dive into what the top 10 looks like in both the 5A and 4A classifications.

Class 5A

Current top 10: Grandview (16-3), Mountain Vista (13-5), Arvada West (15-2-1), Cherry Creek (14-4-1), Regis Jesuit (13-5), Fossil Ridge (14-4), Broomfield (16-3), Prairie View (16-3), Castle View (15-5), Pine Creek (14-3).

There’s no room to blink if teams are hoping to nab one of 5A’s top seeds in the upcoming regional tournaments on May 16-17.

None of the 5A’s current top five — Grandview (seven straight wins), Mountain Vista (10), Arvada West (eight), Cherry Creek (13) and Regis Jesuit (seven) — has lost in more than two weeks.

Castle View, meanwhile, which started last week at No. 2, has fallen all the way to ninth with a 3-3 record since then. Teams like No. 8 Prairie View and No. 7 Broomfield moved in front of the Sabercats thanks to respective win streaks for 12 and eight.

Up at No. 2, Mountain Vista beat Castle View, 11-0, on Monday, behind an offense with five home runs and a complete-game, 14-strikeout shutout from Santa Clara-commit Chase Ruden.

At No. 3, Arvada West stayed in front of defending champ Cherry Creek in the rankings as it continues to be stellar on the mound. In its latest win, sophomore Cooper Vais fanned 15 in an 8-2 victory over Columbine on Wednesday. Vais now has a 0.36 ERA and 78 Ks in 39 innings this season. The Wildcats’ staff, meanwhile, has an ERA of 1.97.

Rounding out the top five, Regis Jesuit survived three errors in a 5-4 win in extras over ThunderRidge on Monday. Sophomore Diesel Bernosky walked it off with his first career home run in the eighth.

Class 4A

Current top 10: Lewis-Palmer (16-2), Falcon (11-3-1), Pueblo County (17-2), Cheyenne Mountain (11-4-1), Golden (15-3), Windsor (14-5), Grand Junction (15-5), Ponderosa (12-6), Glenwood Springs (14-5), Holy Family (11-6).

Defending champ Holy Family cracked into the top 10 thanks to its current four-game win streak. In those four games, Western Nebraska Community College-commit Logan Seifarth is 9-for-14 at the plate with two home runs and eight RBIs.

Lewis-Palmer, meanwhile, moved to the top spot on the back of its seventh straight win. The Rangers started the streak with a two-game sweep over No. 4 Cheyenne Mountain, and on Tuesday, they got their latest in a 14-2 win against Air Academy that saw three RBIs from both AJ Pepper and Hunter Morgan.

Up to No. 2, Falcon beat Cheyenne Mountain, 8-7, on Friday. Ethan Gentz had three hits in the win, giving him seven multi-hit games this season.

Pueblo County was No. 1 at the start of last week but has fallen two spots since despite being on an 11-game win streak. The Hornets, who’ve lost a few ranking points due to their strength of schedule, have outscored teams 129-34 this spring.

Golden, at No. 5, won its 10th straight game on Tuesday, rallying to beat D’Evelyn, 5-4. Sophomore Dylan Paulson is on a 12-game hitting streak and has RBIs in seven of his last eight games for the Demons.

Glenwood Springs, like Holy Family, is new to the top 10 at No. 9. Josh Doll’s go-ahead RBI single in the seventh inning against Summit on Wednesday gave it its seventh straight win.