Whitnash moved into the last eight of the Birmingham Vase with a 2-1 win at Central Ajax but were almost made to pay for missing a host of chances.
Town bossed the first half and were deservedly two goals to the good at the interval.
However, the home side were much improved after the break and pulled a goal back in the closing stages before being denied an equaliser by the woodwork in the 87th minute.
Town, who welcomed back Tony Clarke to their management team, started brightly and Lewis Scott was denied by a fine save before Lee Scott’s powerful header from the resultant corner appeared to be stopped on the line by a stray hand.
Joseph Wright and Lewis Scott had weak efforts saved, while Callum Bell blazed over after good build-up play involving Craig Watkin and Wright.
A Watkin free-kick was put just wide of the post before Town broke the deadlock just after the half-hour mark.
Wright was brought down 25 yards out and of Watkin placed a lovely free-kick into the bottom corner.
Conor Smith wasted two chances before Whitnash doubled their advantage, Stefan Grudinski cleverly heading a corner into the path of Wright who made no mistake.
Smith saw two more gilt-edged chances go begging, while Lee Scott had a goalbound shot cleared off the line after the break.
Wright spurned a one-on-one and an improved Ajax reduced the arrears through Jack Keeling and then hit the crossbar.
In a nervy finale, the returning Danny Nelson had a chance to wrap up the game up for the visitors but his shot from the half-way line went wide of an unguarded net.
Town boss Marc Friend admitted his side need to be more ruthless if they are to challenge for silverware this season.
“We are disappointed we didn’t capitalise on the chances created and really the game should have been out of sight in the first half.
“The reoccurring theme of missed chances could have cost us this match but luckily the right result came to fruition.
“We welcomed back top scorer Danny Nelson for the last 15 minutes which was nice to see him back and we also gave young Josh Aspinall Smith a run out, too.
“Josh is progressing well from our young reserve team and it was good to give him an opportunity of some game time.
“We are pleased with the win and it comes on the back of our last three league victories so we are on form and looking forward to continuing that after the Christmas break.”