The Students went on to make 250-5 declared in their second innings with Slater making an unbeaten century whilst for Warwicks, Keith Barker took three wickets.
This left Warwicks needing 178 to win but they struggled against the bowling of Williamson who took 6-59 from 17 overs.
Ant Botha was not out 63 and Chopra made 33 as Warwicks ended the day on 111-6 and the match was declared a draw.
On Friday, Warwicks travel to Hampshire to play at the Rose Bowl in a Pro40 Floodlit game. Play is due to start at 4.40pm.
You can hear commentary by clicking the link on the BBC Coventry & Warwickshire website.