Chopra (60) and Westwood (67) laid the platform at Edgbaston after Troughton had elected to bat, with the openers putting on 130 for the first wicket. Although the hosts then slipped to 197 for four, Troughton continued his recent good form to guide Warwickshire to 322 for six.
After scoring only 50 runs in his first nine innings of the season, Troughton has made 81 against Sussex, 132 and one against Somerset and now an unbeaten 74 in piling up 288 from his last four knocks.
Meanwhile, Nottinghamshire are just a point behind Warwickshire and they took a firm hold of their clash with Sussex after bowling out the visitors for just 171.
Seamer Andy Carter led the way with three for 41, while Luke Wells was the only Sussex man to pass 50 in a poor batting performance by the south coast side on a blameless Trent Bridge wicket.
By the close Nottinghamshire had more than halved the deficit in reaching 88 for one, and will be aiming to build a convincing first-innings lead on day two, when they will resume 83 runs behind.
Rock bottom Durham's woes show no signs of abating after they under-performed with the bat, although their bowlers put the pressure on Middlesex at Chester-le-Street. After choosing to field, Middlesex's seamers prospered as Paul Collingwood's men were all out for a paltry 102, with Tim Murtagh and Gareth Berg taking three wickets apiece.
Chris Rogers made 59 at the top of the order in reply for Middlesex, who fell from 67 for one to 112 for six although an unbeaten 30 from Berg helped steady the visitors to 144 for seven.
Hampshire captain Jimmy Adams fell nine runs short of his century but led a bold recovery against LV= County Championship Division Two opponents Kent at the Ageas Bowl.
Adams held fort after two wickets had fallen in the first three overs of the match against their promotion rivals.
He made 91 and shared in a stand of 116 for the fourth wicket with Liam Dawson (51) as Hampshire recovered to 292 for nine at the close of the first day.
Meanwhile, Matthew Boyce's unbeaten century was the backbone of Leicestershire's innings against promotion chasing Yorkshire at Grace Road.
Boyce struck 13 fours in his 106 not out to guide Leicestershire to 318 for nine, with Steven Patterson the pick of the White Rose's bowlers after taking three for 54.