West Brom ran riot as they thrashed QPR 7-1 in their Sky Bet Championship encounter at The Hawthorns.
Six second-half goals saw Albion romp to victory and leave shell-shocked Rangers still looking for their first point of the season.
Matt Phillips had given Albion a 29th-minute lead against his former club only for QPR to equalise five minutes later through Joel Lynch.
Rangers were then overpowered after half-time with Kieran Gibbs scoring his first Albion goal in the 53rd minute with Jay Rodriguez netting a penalty two minutes later.
On-loan Newcastle striker Dwight Gayle then opened his account in the 67th minute before he won a penalty that Rodriguez converted.
Phillips then rubbed salt in Rangers' wounds with his second two minutes from time before Hal Robson-Kanu made it a magnificent seven in stoppage time.
Albion's breakthrough should have come seconds before Phillips was on target. Harvey Barnes delivered a perfect cross into the area from the left wing and Gayle only had goalkeeper Matt Ingram to beat.
His side-footed low shot, however, was straight at Ingram who beat the ball away. The loose ball flew straight to Phillips who made no mistake with his low 16-yard shot that whistled past the stranded Ingram.
That looked set to be the signal for Albion to take a stranglehold on affairs but battling Rangers were soon back on level terms after a free-kick was conceded by central defender Kyle Bartley.
Luke Freeman floated a cross into the area and the powerful Rangers striker Matt Smith rose above the Albion defence to nod the ball into the path of Lynch, who made no mistake with a fierce close-range volley.
But any hopes that Rangers had of that signalling an upturn in their fortunes were quickly extinguished at the start of the second half.
The lively Barnes saw his shot crash against the foot of the post and when the ball rebounded to Gibbs he made no mistake from 10 yards.
Rangers were still reeling from that setback when Albion made the game safe. Gayle surged into the area and his run was ended when he was brought down by Josh Scowen. Rodriguez made no mistake from the spot as his shot sent Ingram the wrong way.
Rampant West Brom then gave the scoreline an even more emphatic look when Gibbs' left-wing cross was converted by Gayle. Gayle then had a hand in Albion's fifth - being fouled by Ingram with Rodriguez converting another penalty.
Phillips waltzed across the face of the area to grab his second with a low drive before Robson-Kanu completed the rout when he converted a cross from James Morrison.
The managers
Darren Moore: "At half-time I was happy with the performance and I thought they (Rangers) were hanging on. I told the boys to persevere and they did that. At the top end of the pitch through Harvey, Matty, Jay and Dwight we have got players who have the skill and attributes to put the ball in the back of the net. I thought there was a ruthlessness about them.
"We are delighted to have those four at the top end of the pitch but it is a squad effort. We are trying to move in the right direction and that can only be good for us as a football club. But there are still a lot of hard work ahead."
Steve McClaren: "After 50 minutes I thought we were fine but we made two mistakes and we collapsed. That is unacceptable to QPR fans, unacceptable to us, the players, the club and we have to do something about it on Tuesday (against Bristol City). We need a reaction. In the first three games of the season we fought. I never saw that coming and I am shocked and angry.
"We knew that this was a young squad, talented, but talent doesn't get you everywhere. This was a harsh lesson and we will see who comes out of that. There is a lot of things going on behind the scenes - embargoes, fines and we can't do this and we can't do that - but we are working every day with the loan market open. We need reinforcements to help these younger players.
"After the third goal we couldn't cope and that is to do with mentality. We need to go through the fire to come out the other end and this is the fire. Today I didn't like what I saw and we have to do something about it and make sure it doesn't happen again. Let's see how they react after being hurt."