We're rapidly approaching the biggest part of the summer, and what many consider to be WWE's second-biggest pay-per-view event of the year: SummerSlam. This year's showcase will go down in Toronto in the Great White North, and while we're optimistic about what lies ahead, it's also fun to look back on the history of this great event.

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Over the course of the last ten years, some incredibly memorable moments have taken place at SummerSlam, which includes a series of high-profile title changes. Today, we're going to take a look at the most unforgettable ones from the past decade.

10 CM Punk, 2009: World Heavyweight Championship

It’s hard to believe that CM Punk was competing in world title matches ten whole years ago, but it’s the truth. At the time he was locked in --and we don’t say this lightly-- the literal feud of the year with The Charismatic Enigma Jeff Hardy.

In their final big pay-per-view match, Punk was able to get the best of Jeff in what many considered to be his ‘home turf’ of a TLC match. It was a career-defining win for The Straight Edge Superstar, who continued to go from strength to strength.

9 Randy Orton, 2011: World Heavyweight Championship

Much like the first entry, Randy Orton was in the midst of an incredibly entertaining feud between himself and WWE veteran Christian. The two men had battled back and forth for the WHC in a series of big-time matches until finally, The Apex Predator put Christian away for good.

He did so with one of the most incredible RKOs you’ll ever see onto the steel steps, claiming the belt back in a really tense and brutal No Holds Barred match. In our opinion, it’s one of the finest moments of his career.

8 Randy Orton, 2013 - WWE Championship

We’re sticking with the Orton praise for now, but we’re heading two years into the future next. Daniel Bryan had just defeated John Cena to win the WWE Championship for the first time ever, when Randy Orton (who was Mr. Money in the Bank at the time) came down to the ring in order to tease a cash-in.

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Just when it looked like he was having second thoughts, Orton stunned the world by turning heel and aligning with Triple H – who had also turned heel in the process. The rest, as they say, is history.

7 Paige, 2014 - Divas Championship

You're probably sensing a theme here, as we’ve arrived at another high-level feud: Paige vs. AJ Lee. The English sensation had lost the title back to a returning AJ after initially winning it on the night after WrestleMania XXX, but at SummerSlam, Paige was able to prove why she was one of the fastest rising female stars in the history of the company.

She put AJ Lee away with ruthless efficiency, ensuring that this wouldn’t be the last we’d see of these two in the ring together.

6 Brock Lesnar, 2014 - WWE World Heavyweight Championship

When Brock Lesnar broke the streak at WrestleMania XXX, it was only a matter of time until he became a world champion in WWE again. That moment occurred a few months later at SummerSlam 2014, when The Beast Incarnate quite literally squashed John Cena to capture the belt.

It was one of the most stunning world title matches in WWE history, as the 16-time world champion Cena barely got two moves in. He was well and truly battered, and it was a fascinating sight to see for the WWE Universe.

5 Sasha Banks, 2017 - RAW Women’s Championship

After having a number of short world title reigns, many fans were led to believe that Sasha Banks’ big win over Alexa Bliss at SummerSlam 2017 would be the start of something special for her. While that didn’t exactly turn out to be the case, we still got a great match out of it.

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It was well known at the time that these two women didn’t really like each other outside of the ring. Instead of being petty about it, though, they both brought a phenomenal intensity to this match that we hadn’t really seen before.

4 The Usos, 2017 - SmackDown Tag Team Championships

It’s The Usos vs. The New Day at SummerSlam. In many ways, we don’t even really need to say much more than that. Whenever these two teams are in the ring together they create magic, and that’s no exaggeration.

On this occasion, though, it was Jimmy and Jey who were able to get the job done, capturing the titles once again in the process. At this point, they really were on fire in a fresh heel role and New Day were as good as ever, which made the decision to put this match on the pre-show all the more bizarre.

3 Dean Ambrose & Seth Rollins, 2017 - RAW Tag Team Championships

The reunion of Dean Ambrose and Seth Rollins really was special, because fans had been waiting to see it for so long. When Seth first turned on Dean, a lot of fans weren’t entirely sure how it was going to work out, but a few years on, it’s fair to say that it had the desired impact.

It seemed almost obvious to see that they were going to win the titles when their match against Cesaro & Sheamus was announced, but that didn’t stop them from putting on an absolute barnburner of a bout.

2 Ronda Rousey, 2018 - RAW Women’s Championship

The best thing about this title win was that it felt so real. Of course, given the first (fair) opportunity at doing so, someone like Ronda Rousey would walk all over Alexa Bliss before capturing the RAW Women’s Championship.

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Ronda was red hot at the time after her reaction to Alexa’s shenanigans at Money in the Bank, and it was great to see her take it out on Little Miss Bliss on such a big stage. From this point on Ronda had a really solid run with the title, leading all the way up to WrestleMania 35.

1 Roman Reigns, 2018 - Universal Championship

After waiting for so long to see it, we finally got the moment we were all waiting for: Brock Lesnar being dethroned as the Universal Champion. While he may have got it back just a few months later, the way in which Roman Reigns was finally able to beat him played out really nicely.

The tease of including Braun Strowman in the mix was a bit odd but fun at the same time, and the match was short enough to ensure that the fans were excited as opposed to lethargic.

NEXT: The 10 Youngest Intercontinental Champions In WWE History