Truro 1 Halesowen 2
Manager Matt Clarke hailed Halesowen's success at ambitious and in-form Truro as "a massive win" in their first-ever competitive game in Cornwall.
With the storms abating at exposed Treyew Road, the overnight stay paid early dividends when Aaron Griffiths was up-ended in the seventh minute, allowing goal machine Stefan Moore to tuck home his 19th of the season from the penalty spot.
Visiting goalkeeper Nick Bussey then kept out a 10th minute header but Halesowen continued to look lively with Craig Connor and Griffiths acting as wing-backs, as both Moore and Griffiths went close midway through the half.
The Tigers' task was made more difficult when on-loan Steve Adams was dismissed with a straight red card in the 39th minute for a poor challenge on brave Jamie Hood.
Ten-man Truro then made a double substitution at the interval and forced the Yeltz to defend deeply to keep out several dangerous crosses with Henry Eze in commanding form.
But Halesowen still created chances with Simon Johnson only stopped by home goalkeeper Rice with his first touch in the 54th minute.
The visitors pace gave them breathing space to double the lead when Johnson latched onto the ball from the right and cut inside to drive home after 64 minutes.
Truro had late hope when influential home midfielder Taylor crossed for Les Afful to reduce the arrears in the 70th minute, but Halesowen snuffed out further late threats and with two minutes remaining Moore was denied again.
Truro City: Rice; McConnell, Hodges, Pugh (Ash 45), Gaia, Adams, Taylor, Martin, Yetton (Watkins 74), Afful, Walker (Broad 45).
Subs not used: Clay, Brooks.
Halesowen Town: Bussey; Connor, Morley, Eze, Hood, Breward (Blenkinsopp 72), Johnson, Denny, Moore, Griffiths, Rickards.
Subs not used: O'Brien, Pearce, Clarke, Flower.
Referee: M Pottage (Wincanton)
Attendance: 429