Carnegie won 26-19 as they rounded off their group campaign with a bonus point success at Scarborough’s Silver Royd ground.
In-form Jersey’s only try came via Brendan Cope’s converted effort in the fourth minute meaning determined Yorkshire protected their line for fully 76 minutes thereafter.
The victory saw them move into the eighth and final qualifying spot for the quarter-finals.
However, the final eight teams through to the knockout stages cannot yet be confirmed as Cornish Pirates’ game against Hartpury on Saturday was postponed due to a waterlogged pitch and has to be rearranged.
Carnegie full-back Chris Elder continued his recent excellent form with another two tries as his side built up a 26-13 interval lead.
Stevie McColl and Harry Newborn scored their other tries with Will Homer – back from suspension – slotting three goals.
It was the first time in seven games Jersey had been defeated since Carnegie, in fact, beat them in November.
“I was pleased, especially for them to score just one try against us,” said Lowes, as his side hit straight back to winning ways after losing at London Scottish the previous week.
“Jersey didn’t really break us; I thought there was some really good stuff in defence and some of our hits were really strong.
“We gave too many penalties away in the first half at the ruck but we addressed that at half-time and once we took them away we handled field position quite easily.”
Both sides were reduced to 14 men in the second period as Carnegie’s Matt Smith and Jersey’s James Voss were yellow carded but it was the hosts who held firm, the Channel Islanders limited to just penalties from Cope who finished with four.
Amid recent freezing conditions, the game only went ahead after a pitch inspection on the morning of the game and a big effort by the Scarborough ground staff.
Lowes added: “Jersey came up and had a look at the pitch in morning, too, so both were happy to play.
“The pitch was in real good nick considering the adverse weather.
“A local farmer came down with a tractor and got on the field to start spiking it which was great.
“Every club that has had us, like Huddersfield as well as Scarborough, have been really receptive.
“They worked hard to get it on and I’m glad they did.
“We won’t worry about whether we’ve qualified or not. We can’t control other results.
“A five point win is enough to concentrate on and now we’ll look towards our Championship game with Hartpury at Headingley next Sunday.”