Joe Tiffany led the way with 118 not out and Josh Lowe also made the Kirkby bowlers toil as he finished unbeaten on 68.
Darrol Lewis added another 43 as Seamer racked up 273/2. Howard Mudd was the only bowler to enjoy a breakthrough, taking both wickets to fall.
Martin Thompson and Martin Charlton were the focal points of Kirkby’s response, making 71 not out and 34 respectively, but they were all out for 168, 105 runs short.
Flixton 3rds are top of the pile after two games, with no-one managing to make a perfect start. They followed up last week’s draw with an impressive 65-run win over Flamborough.
Marley Ward’s 81 was the top score and he was backed up by Daniel Hill as the leaders set Boro 182-8 to chase.
Flamborough’s leading performers were Derek Moyse (3-27) and opener Luke Dixon, who made a half century in reply, but John Sowden’s 3-33 ensured Flixton collected 19 points.
Nawton Grange picked up their first win of the campaign as they held their nerve to topple Ryedale.
A total of 181-8, boosted by Neil Ward’s 85, was good enough to claim victory. Ryedale’s Jordan Newton and Jim Boyes both reached 38, but Grange also had two players with matching returns, as 4-36 from both George Bentley and Nathan Marwood, ended Ryedale’s innings on 152.
Bowlers were on top at Muston, where Wykeham 2nds’ 148 was enough to take the points. No-one managed more than 25 in the visitors innings as Matthew Kings claimed 5-38 and Scott Orange had three victims.
Kings then produced the highest score of the match after tea, with 28, but Steve Day and Scott Wardman shared seven wickets to send Muston packing for 114.
Will Wood and Nick Hodgson shared top billing in a tale of two innings in Division Four. The Cayton 3rds duo scored 92 and 89 not out as the hosts smashed 213-7 against Wold Newton 2nds.
The reply was a much more tame affair, as Wold Newton crawled to 81-3 from their 40 overs.
Snainton’s Luke Smith was another batsman on form as he contributed 61 of his side’s 208-7 against Cloughton 2nds. Paul Nicholson contributed 30, but Leigh Watson ran the show in the second innings, collecting 7-23 as Cloughton were back in the pavilion for just 44.
Sherburn 2nds’ trip to Filey 2nds ended in disappointment as the hosts won by five wickets to remain unbeaten.
Matthew Lickes’ 40 was the most notable effort in Sherburn’s 155-9, although Jonny Pickard also contributed 29. With the ball, Filey’s Jonathan Hunter secured 4-55 and Lewis Adams added three more wickets.
The total was not enough to trouble Filey, who got home with Mike Johnson (53) and Nathan Vernon (42) at the forefront of their run chase, despite Pickard taking 4-23.
In Division Five, Ganton were the day’s top scorers and move up to third in the table after the best of a draw againt Ravenscar 2nds.
Dan Reardon (70) and Anthony Allison’s half century set Ganton on their way to an imposing 252-8. Ravenscar were never in the hunt, but stuck at their task to make 132-6, John Nelson making 42 and Jon Murrell 40, as they fell well short.
Lowest score went to Forge Valley 3rds, who made just 48 as they fell to a huge 165-run defeat to Valley Bar Nomads. Their 213-9 was based around 72 from Anosh George and 35 from Craig Best, while Colin Arbott rubbed salt into the wounds of his former club with 26.
Neil Arnott’s 4-36 were the best figures of the match, but Nomads’ skipper Tony Hulme later bagged 3-11 as Forge Valley caved in.
Thornton Dale 2nds and Wykeham 3rds contested an excellent match, with Wykeham coming out on top by 23 runs.
Wykeham posted 144-7 with Ian Thompson top scoring with 47 and George Shannon adding 28. John Ellis took 5-33 for Thornton.
Shannon also starred with the ball, taking 4-16, along with Adam Brown’s 3-34, as Thornton were all out for 121, Paul Waring making 23.