Huddersfield caught the visitors cold and took an 11th-minute lead with a break from Joel Hinchliffe who put captain Nick Sharp in for a try, Hinchliffe adding the extras.
Ionians quickly responded with a penalty but it was penalty tries either side of half-time that put them 17-7 ahead.
Winger Danny Hughes extended that with a well-taken try but with 10 minutes left Huddersfield hit back, Elliot Hodgson going over and Chris Bell converting to make it 22-14.
Ionians showed their class by rounding off the best move of the match with a try from winger Steve Slingsby to add the bonus.
Otley thrashed Sedgley Park 39-10. Freddie Watson picked up at a scrum allowing Stephen Depledge to break wide and set the ball down the line for full-back Arnie Ellison who returned the compliment by kicking ahead and giving Depledge a 40-metre run in. Ellison grabbed a second, Depledge converting and on 30 minutes hooker Ben Steele grounded as the pack drove over.
A surge from Park brought them a brace of tries from winger Curtis Strong but Otley re-imposed their superiority in the second-half. They scored tries through No 7 Matt Heaton, winger Alex Beaumont and a superb break from centre Jack Mackie whick took him to the line; Depledge converting to close a fine performance.
A lack of possession cost Hull dearly as they slumped to a 22-12 defeat at the hands of Birmingham Solihull.
In the first half especially, Hull simply could not get their hands on the ball and Birmingham should have scored more than the 17 points that they managed.
However, Hull did pick up in the second half and despite losing a man to the sin bin, they grew into the game and started to put pressure on their opponents.
They scored two late tries through second row Rob Devonshire and winger Aiden Holland but ultimately ran out of time.
Harrogate captain Sam Bottomley – playing his 150th game for the club – inspired his team to a 34-29 win at Luctonians.
Luctonians scored first, Adam Knight scoring in the corner, converted by Geraint Langdon. Bottomley responded for ‘Gate when he jinked his way over for a try converted by Joe Rowntree.
Luctonians scored two converted tries through prop Ashley Horner and centre Jon Hughes. Three Rowntree penalties put Harrogate in striking distance before a clever Callum Irvine chip was seized on by Lewis Minikin to score. Harrogate surged ahead in the second half; Luke Edwards crossing and Rowntree adding two penalties.