The Buddies boss has no doubt that the hard-fought victory over Accies, which came via Lee Mair's injury-time header, has underlined that his summer squad building has provided Saints with the extra firepower to consolidate their top-six status.
But Lennon is also aware that with County having lost their 40-game unbeaten league record at the hands of St Johnstone last weekend they will come to Paisley determined to bounce back.
Tomorrow's tussle will be the first between the clubs since Lennon's men edged a Scottish Cup replay 2-1 in Dingwall back on Valentine's Day and the Saints' gaffer has no doubt another tight contest is in the offing.
He said: "The great thing for us in getting the win over Accies is that we have responded in the way we needed after the Kilmarnock defeat. There was not a lot wrong with our performance at Rugby Park except for the fact we just did not take the chances we created.
"Against Accies we faced a very well organised side and it forced me to change things around tactically. I started with Lewis Guy up front but there was no space for him and I made the conscious choice to go with two big guys by bringing on Stevie Thompson and pairing him with Sam Parkin.
"Ironically it was Lee Mair who supplied the header to get us through, but the great thing from my perspective as a manager is that I have the options in place to change things if I need to.
"Also, experiences last season against the likes of Ayr have made me aware that sometimes you need to make these decisions earlier to give them time to impact.
"But now we have our fourth cup quarter-final on the bounce to look forward to and we are going into the County game on the back of a clean sheet and a home win. These are all very big positives.
"As we showed against Accies we are now better suited to making the most of chances that come our way."
Lennon also took time to salute Mair whose strike booked the last-eight League Cup berth.
The Buddies boss said: "Lee has been a big part in the development of Marc McAusland and the two of them have formed a solid partnership at centre-back after the injury set-back for Darren McGregor.
"But on Tuesday Lee used all his experience. He saw our best hope was by going direct and before he scored he drew an outstanding save from Kevin Cuthbert in the Accies goal. To a large extent Lee is an unsung hero for us, but he just does a great job."