The Glassboys had a tricky time from the off and conceded when Josh Castiglione drove forward and crossed for Jonny Edwards to glance home a 14th-minute header.
It had been a baptism of fire but livewire Mills drew a foul from right-back Ed Asafu-Adjaye just before the half-hour mark, keeping his cool from 12 yards to restore parity and inject life into the visitors.
Kayelden Brown and substitutes Andre Landell and Alex Fletcher all went close in a second half that ebbed and flowed with Adam Murray going as close as anyone to winning it for Royston but Stourbridge manager Mark Yates declared himself satisfied with his side’s work.
“We met a bit of a wounded animal, they haven’t started how they wanted to and had a big centre-half playing as a centre forward, a big battering ram,” said Yates.
“We did not start too well but dealt with it in the end and got a really good point, we played some good football at times without playing that well overall.
“Credit to the lads, they showed spirit and our centre-halves were outstanding in the second half. We deserved our point.
“We had a few chances but so did they. We didn’t get out of the traps for half an hour, they were dominant and turned us but once we found that spirit and fight we had our moments and four, five or six openings.
“It was two decent teams having a right good go.”
The point keeps the Glassboys in the cluster of teams near the top of Southern League Premier Division Central, albeit from a game more than most of the others.
Glassboys: Price, Green (Bustin, 80), J Brown, Morris, Riley, Birch, Deeney, Knights (Landell, 58), K Brown, Mills (Fletcher, 64), Peniket.
Unused subs: Nicholls, Derrick.