The Lions will resume on day two at 4-53, needing another 48 runs for first innings points.
Impressive bowling was the highlight, for both sides.
Leitchville-Gunbower elected to bat after winning the toss and started well enough.
English import Vikai Kelley and skipper Tyler Jones got the Bombers away to 24.
Kelley (12) was the first to fall, expertly stumped by Regis Chakabva from the bowling of Luke Thompson.
Jones, fresh from a century against Echuca the previous week, looked the most comfortable of the Leitchville-Gunbower batsmen.
But his knock came to an end on 26 when caught by that man Thompson from the bowling of Simon Van Duinen.
Van Duinen, in his second season with BLU, made it a double breakthrough when he trapped Josh O’Shea (1).
When Thompson followed up shortly after with the wicket of Liam Keath (9), the Bombers were wobbling at 4-50.
Despite cameos from Kurt Brereton (14) and Simon Tatt (11), BLU’s bowling attack held the upper hand.
Six different bowlers finished with wickets as Leitchville-Gunbower was bowled out for 100.
Van Duinen (2-20) and Thompson (2-22) did the early heavy lifting, ably supported by Rathika Rajakumara (2-12) and Amila Gunathilaka (2-25).
Special mention to Jeremy Felmingham, who returned the figures of 1-8 from eight overs, featuring five maidens.
BLU’s chase was on the back foot early with openers Josh Cairns and Liam Hamilton in the sheds with just seven runs on the board.
That brought Zimbabwean ace Chakabva to the crease.
But his stay would prove a short one as spearhead Blake Gelletly produced a gem of a delivery to bowl Chakabva for eight.
The home side was 3-16.
Some counter-attacking batting from Rajakumara got the scoreboard ticking over, but the Lions lost another wicket late in the day when Declan Pearse was run out for 10.
Rajakumara will resume on 26 and James McPhee, having survived 15 deliveries, has the chance to get off the mark this coming Saturday.
Gelletly (2-8) was the pick of the Bombers’ attack, while Keath (1-12) was the other to collect a wicket.