Liam Trevaskis, Chris Wright slice through Northamptonshire top order

Liam Trevaskis and Chris Wright sliced through Northamptonshire's top order as Leicestershire closed in on a victory that would sign off their Rothesay County Championship Division Two title triumph in style.

The Foxes, already confirmed as champions last week, declared and set Northamptonshire an improbable 501 to win at Wantage Road following Rishi Patel's 76 and an unbeaten 30-ball half-century by Ben Cox.

Left-arm spinner Trevaskis took three wickets, with seamer Wright - playing his final game prior to retirement - capturing the other two to reduce the home side to 120 for 5 before bad light halted play.

Northamptonshire's Rob Keogh top-scored with 42, passing 10,000 runs across all formats in the process, but his side's slim hopes of staving off defeat largely rest on Saif Zaib, unbeaten on 20 at stumps.

Leicestershire resumed with an overall lead of 326 and eight wickets in hand, but they were initially stifled by a tight spell from George Scrimshaw, who found some movement in both directions.

However, it was a straight delivery from the seamer that removed Lewis Hill, leg-before for 38 and Patel then took command, punching a series of boundaries and bringing up his half-century with a straight drive off Stuart van der Merwe.

Van der Merwe was also slog-swept for six by the Foxes opener, but there was success for his fellow rookie Nirvan Ramesh when Stephen Eskinazi reverse-swept the off-spinner and deflected onto his stumps.

Although Patel's hopes of another century to back up his 114 against Kent last week were dashed shortly before lunch when he nicked Zaib behind, the champions chose to bat on into the afternoon session.

Yet Cox's lightning half-century ensured that the innings continued for only five more overs - enough time for Leicestershire to pile up another 53 runs and extend their advantage to exactly 500.

Cox bludgeoned the vast majority of those, scooping Scrimshaw for six and then flicking Ben Whitehouse over square leg and out of the ground before a booming four over the bowler's head signalled both his 50 and the declaration.

Logan van Beek and Wright gave away very little at the start of Northamptonshire's second innings, with the ball rolling across the boundary rope just once during the first 11 attritional overs.

Wright, bringing down the curtain on a 22-year professional career, dismissed both openers as Arush Buchake was caught behind pushing at a ball that left him before Lewis McManus drove straight to gully.

Having edged Wright to the third boundary to reach his career landmark, Keogh gained a life soon afterwards when he nudged Josh Hull through the slips for four more, but settled down as he and James Sales steered their side to tea.

The partnership progressed to 67, but Keogh's good fortune ran out soon after the restart as he aimed an ambitious drive at Trevaskis and this time Patel safely pouched the chance at slip.

Sales departed in the left-armer's next over, caught behind off a bottom edge and Trevaskis then trapped Justin Broad lbw in a prolonged spell - partly enforced by the darkening clouds which restricted Leicestershire to slower bowling.

Patel came on to deliver a single over of leg-breaks before the deteriorating light brought an end to proceedings, with Leicestershire needing five more wickets to wrap up victory on the final day of the season.