Ryder averages more than 60 for Otago in first class cricket and has plenty of work ahead of him if he is to reach the milestone again.
But the punishing left hander, playing in just his 12th first class game for the province, was in fine touch at the Queenstown Events Centre yesterday with a 73 ball half century.
He was undefeated on 52 when stumps were pulled. Earlier, Neil Wagner picked up his 20th five wicket bag to help dismiss Wellington for 297. In reply, Otago is 162 for three.
Stephen Murdoch top scored for the visitors with 121 _ his seventh first class hundred.
Play got under way at the later time of 3pm on Saturday due to a ground delay.
Otago right arm Jacob Duffy secured a fortunate early breakthrough when the experienced Michael Papps chopped on. He spun round to look for the ball, only to see it land on his stumps.
Ryder and Craig Smith picked up the other two wickets to fall.
Murdoch (74) and James Franklin (25) were undefeated with Wellington 179 for three at the end of the first day's play.
Yesterday, Murdoch went on but Franklin was only able to add a further four runs to his overnight score.
Wellington got into a dominant position at 266 for four but the new ball brought about a rapid demise.
Wagner was the major factor in Wellington's sudden change of fortune. He bowled Tom Blundell (31) and then picked up the key wicket of Murdoch.
Jeetan Patel, playing in his 100th first class game for Wellington, has played some valuable knocks against Otago but he perished second ball.
Duffy (three for 72) chipped in from the other end, accounting for Alecz Day before Wagner (five for 73) completed his five wicket bag when he nicked out Matt McEwan.
Wellington lost its last six wickets for 31 runs and handed the initiative back to Otago.
Aaron Redmond (50) and Hamish Rutherford (36) set a solid base with an opening stand of 78. But Redmond and Michael Bracewell were dismissed with consecutive deliveries, leaving the Volts 98 for three before Ryder and Ryan Duffy (12 not out) settled in.
In Whangarei, Central Districts requires 325 to win with nine wickets in hand when its game against Northern Districts concludes today. It will resume on 23 for one.
At Colin Maiden Park, Auckland reached 294 thanks to a fighting century by wicketkeeper Brad Cachopa. Edward Nuttal was the pick of the Canterbury bowlers with three for 42. At stumps on day one, Canterbury was four without loss.
