Sale scored first-half tries through Tom Curry, Rob Webber, Sam James and Chris Ashton, however, Gloucester led at the break with Tom Seabrook, Ben Vellacott, Matt Banahan and Lewis Ludlow sealing their bonus point.
In a lung-busting second half, Byron McGuigan touched down for the hosts, while Dom Coetzer and Vellacott struck back.
There was still time though for AJ MacGinty to touch down and Denny Solomona to win it with an outstanding effort.
Diamond reserved praise for Solomona, while chiding the national setup: “Denny now tops the try scorers in the Premiership but the selectors don’t seem to think he fits the bill, whereas every time he puts a rugby shirt on for Sale he scores.
“Remarkably Luke James has just been called up for the u-20s but he’s been ignored for the past two years, even though he’s played 55 games out of a possible 66 for us.
“England need to get their act together.”
The win ensured Sale finished seventh in the Gallagher Premiership table. They now have to wait overnight to see if they will make it into the Champions Cup, depending on the outcome of La Rochelle versus Lyon in the French Top14.
Diamond added: “I thought we were very poor in defence and good in attack. It was like a Super 15 game. We needed four tries and we had to play that way.
“By the way the other results have gone it’s irrelevant to us, we’re not in sixth anymore so we’ll probably miss out on the cup for Europe. That was not today’s performance but it was in past games.”
The game was full of attacking talent but the fact Gloucester conceded 46 points will be cause for concern for Johan Ackermann with a semi-final against Saracens to come.
Ackermann fielded a weaker side than usual in preparation for next weekend but was still pleased with his side’s efforts.
“I’m just proud,” said the head coach. “I just talked to the players and I salute them for the effort they’ve put in. Obviously a few of those guys haven’t played for a few weeks.
“There was a new centre combination and a fair bit of change, and therefore it’s always a bit disruptive for your rhythm.
“I thought our back row was good today. Our locks worked hard and did good things. Matt Banahan, in a different position, was quite good.
“It gives us options now and a lot of the guys have put their hands up. All that’s left is to see who is 100 percent ready on Monday, from an injury point of view, and then make sure we get 23 guys who are ready to fire.”
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