The one-goal loss in front of more than 1,400 fans at Hull Arena came 24 hours after a more disappointing reverse in Whitley Bay, when Cloutier's side went down 5-3 to struggling Newcastle Vipers.
Panthers – whose bid to end their long wait for a top-flight league title had stuttered of late – arrived in East Yorkshire full of confidence after thrashing Dundee Stars 12-2 at the National Ice Centre on Saturday.
But it was clear from the opening face-off that they were unlikely to be given another easy ride and it was Stingrays who took the lead on the powerplay in the 12th minute when British forward Matt Davies finished smartly for his second goal in as many nights.
Panthers hit back to level with 39 seconds of the first period left with an excellent solo goal from Billy Ryan before Ian McDonald tipped in a Corey Neilson shot to put Panthers ahead on the powerplay in the 26th minute.
But Stingrays restored parity with a powerplay marker of their own with in-form Jason Silverthorn unleashing a superb shot into the top corner at the halfway stage – his third strike in as many games.
However, with both sides pushing for the breakthorugh goal, it was Panthers' Jade Galbraith who scored with a bullet shot on the powerplay 13 minutes from time to leave the home side empty-handed, but full of confidence.
"I think against Nottingham and against Sheffield last week, we've shown we can compete with the so-called big clubs," said Cloutier.
"I was looking for a response from my players after the Newcastle defeat on Saturday and I got what I was looking for.
"We are trying to take positives from every game we play and there were lots of them against Nottingham."
Stingrays were undone by three goals in the opening 16 minutes at Newcastle as Toms Hartmanis's opener and powerplay strikes from Kyle Sibley and Patrik Forsbacka put the home side in control.
Goals from Trevor Read and Silverthorn made it a one-goal game but Vipers restored their two-goal cushion through Dean Holland within 16 seconds and Forsbacka's second of the night early in the third.
Davies opened his account for the season to make it 5-3 but that was as close as Stingrays got.
Stingrays will hope to capitalise on the increased interest they have attracted in terms of crowd numbers next weekend when they enjoy a home double header.
First they welcome leaders Belfast Giants to Hull Arena on Saturday (7pm face-off), followed by a a visit from Newcastle on Sunday (6pm).
Sheffield Steelers were left licking their wounds when they were beaten 4-0 at home by Elite League newcomers Braehead Clan on Saturday.
Ben Simon's team – missing Rob Globke and Mark Thomas through injury and Derek Campbell due to suspension – outshot the visitors by 38-19 but were undone by goals from Ryan Campbell, Adam Walker, Bobby Chaumont and Brendan Cook.
Coupled with Belfast Giant's 5-3 win over Dundee Stars, Steelers are now seven points behind the leaders albeit with three games in hand. They remain in second place ahead of rivals Nottingham on goal difference.
They are next in action on Saturday, October 23 when they welcome Coventry Blaze to Sheffield Arena (7pm) in the Challenge Cup. The Blaze comfortably beat the Steelers 5-1 in their first cup meeting earlier this month at the Skydome Arena.
They will then travel to Cardiff in the league on Sunday night.