After Kane unmasked, he turned on his former tag team partner Rob Van Dam. Inevitably when this thing happens between wrestlers, they get put in matches, in this case several, and Rob did nothing but get thrown, slammed, punched, choked, and stepped on. The only match in their series Rob actually won was a steel cage match, where you need to escape to win. When Kane tossed the helpless Rob through the cage, the referee counted it as Rob escaping.
Another inverted example had a cage match between Vince McMahon and "Stone Cold" Steve Austin. Austin beat Vince so badly and so bloody the match had to be stopped and McMahon had to be wheeled out on a stretcher, but then Austin jumped on the stretcher to continue punishing his boss.
General example: Any match involving one of the members of DX eventually devolved into this.
Specific example: Shortly after "Stone Cold" Steve Austin's infamous 'accident', The Rock was in a match with the Big Bossman. Bossman pulled his usual Heel tactics, which resulted in the Rock snapping and beating him, the ref, several MORE refs, and the paramedics into states that greatly resembled comas with anything and everything he had on hand. Leaving him standing in the center of the ring, staring about wildly with a pile of destroyed humanity all around him. The point was to cast suspicion on The Rock for Austin's accident, you see.
During the kayfabe (pre-mid 1990s) era, when most wrestling TV programs pitted top and mid-level talent against jobbers, a promoter would sometimes push a villain as an unstoppable Monster Heel by having him continue beating jobber wrestlers (and sometimes anyone else) well after they could have scored a victory. The idea was always to demonstrate the heel's power — and often, devastating impact of his offensive arsenal — and (the main goal) rally the fans to call upon the promotion's top babyface to demand a match with the heel and give him his comeuppance.
Though the referees stopped her before it went too far, at Survivor Series 2004, Lita was well on her way to unleashing one of these on Trish Stratus, having already smashed her face into a chair, the ring steps, beaten her with the chair, pummeled her in the face, and was choking her by the time several refs were finally able to pull her off. Even at that, she still managed to get away from them and go back for more.
Mick Foley has given and received many of these in the course of his career.
The Two Man Power Trip (Triple H and Stone Cold) delivered an absolutely hellacious beating to the Hardy Boys and Lita. It's pretty uncomfortable to watch, especially as they humiliate and destroy Lita with a chair... not that they needed the chair.
He gave a lot of these over the course of his career.
Brock Lesnar, especially his match with Cena at Extreme Rules 2012.
The Shield (Dean Ambrose, Roman Reigns, and Seth Rollins) have been doing this to pretty much everyone they come into contact with since they debuted in late 2012. They claim it's in the name of "stopping injustice" but the end product has been little more than senseless violence (as they also claim to work for no one so it must be implied they choose their own targets).
Back when they were getting their start in WWE, Jamal (Eddie Fatu, who would later become Umaga) and Rosey (Matt Anoa'i, Roman Reigns' older brother) formed a tag team called "Three Minute Warning". Eric Bischoff would warn people who were getting on his nerves that they would have three minutes to entertain him/make their case or he'd send these two out and they'd beat the crap out of his target.
Samoa Joe delivered a brutal one to Christopher Daniels at the TNA Genesis 2005 show, the two were in a team elimination Match and they wound up winning but Daniels scored the pin which Joe had wanted. After a bit of arguing the two seem to coincide only for Joe to turn and knock Daniel's head out with a kick. He then busted him open with a chair shot with Daniels bleeding and semi conscious unable to do anything helpless beofre Joe's onslaught as he wound up delivering several Muscle Busters to him, one onto a Chair.