Having declined the option of bowling first, Yorkshire won the toss and, after choosing to bat on a firm pitch, ended the day on 177 for four.
They were made to work hard for runs against a Warwickshire side playing their first home match of the season and fancied to pose one of the principal threats to the White Rose’s aspirations of winning a third successive title.
A Bears attack including the fit-again Chris Woakes and Boyd Rankin, who returned to the team in place of Chris Wright and Oliver Hannon-Dalby, reduced the visitors to 85 for four before Ballance and Jack Leaning, both of whom finished the day with exactly 50 runs to their name, dug in to add an unbroken 92 in 28 overs.
Opening pair Adam Lyth and Alex Lees put on 46 before three wickets fell for just 10 runs in the space of 40 balls.
Rikki Clarke struck first in spectacular fashion when he knocked out Lees’ off and middle stumps for 19.
Lyth then top-edged a pull at Rankin to mid-on, where Ian Bell took the catch at the third attempt to send the opener packing for 19.
Captain Andrew Gale reached only five before misjudging a swinging, full-length ball from Keith Barker which thundered into his stumps.
Jonny Bairstow, scorer of a superb century in this fixture last season, again looked in excellent nick and reached 20 from 25 balls before being bowled by England team-mate Woakes attempting a drive to one which kept low.
At 85 for four, Yorkshire were under pressure and what followed was a period of compelling cricket where the scoring-rate was low but the entertainment high. It was intense, competitive, highly-skilled stuff as Ballance and Leaning batted with great diligence against probing seam bowling led by Woakes and Clarke.
The fifth-wicket pair showed the tenacity and resolve of champions to steer their side away from danger in a match which, although very early in the season, could transpire to be of huge significance to the title equation five months down the line.