David Hussey marked his final game for Nottinghamshire with a century that could go a long way to helping his side fight off relegation from Division One of the LV= County Championship.
Hussey and Michael Lumb both reached three figures as Notts recovered from 76-4 to reach 378-8 after being put into bat by Somerset at Trent Bridge.
The Australian will leave Nottinghamshire at the end of the season but added to his crucial role with the bat in Saturday's Yorkshire Bank 40 success with an innings of 125 - adding 214 for the fifth wicket with Lumb.
Hussey strode out after Samit Patel had lost his off stump to Alfonso Thomas to depart for 16.
Lewis Gregory, who finished with 3- 89, created early alarms by removing Steven Mullaney and James Taylor in quick succession, with neither man playing a shot at the ball.
Inexplicably, before he had scored, Hussey also decided to shoulder arms and looked fortunate to survive a confident lbw appeal from the bowling of Thomas.
From then on, apart from a sharp chance which was missed by James Hildreth, when he'd scored 58, and a leg side spill by wicketkeeper Craig Kieswetter just before his eventual downfall, it was Hussey's day.
His 43rd career century - and 23rd for the county he first joined in 2004 - was brought up with an elegant cover drive from Gregory, reaching the milestone from 144 deliveries with 16 fours.
Lumb passed 1,000 championship runs for the season during his stand of 214 with the 36-year old, a county fifth wicket record against Somerset.
Lumb celebrated his fourth century of the season, arriving from 239 balls with 12 fours, with a pulled six over midwicket before playing around a full-pitched delivery from Gregory to depart for 107.
Chris Read fell towards the end of the day for 39, leaving 20-year debutant Brett Hutton, in for the injured Andre Adams, to score his first championship runs in the final over.