MELBOURNE—Fernando Verdasco stunned Rafael Nadal in the first round of the Australian Open, but who can forget what happened in Melbourne seven years ago?

Verdasco certainly hasn’t forgotten.

In 2009, Verdasco lost to his countryman in five sets in an epic semifinal. Since that night, the world No. 45 has watched tapes of the match.

On Tuesday, Verdasco turned the tide, beating Nadal, 7-6(6) 4-6, 3-6, 7-6(4), 6-2. In the 2009 semifinal, former No. 1 Nadal beat Verdasco, 6-7(4), 6-4, 7-6(2), 6-7(1), 6-4.

The 32-year-old admitted that he’s watched the 2009 semifinal at least 10 times on TV.

“I saw the match many times on TV after,” said Verdasco. “I was aggressive with my serves. Maybe I needed a little bit more in the return. But with 4-4 I have love-30 on second serve. I think in that point of the match, it was a key point to maybe break and serve for the match. Maybe I was a little tight. I miss a backhand to the net. I was not, of course, as aggressive [as] today.

"After he came back in that game from love-30 and wins his serve with 5-4, then he broke my serve and won the match. Today I was just trying to be as aggressive as possible, but also not, like so crazy. Sometimes if you do like what I did today, you put all the balls outside. It's like, ‘This guy's crazy.’ He just hit everything and he miss. But when they are coming in, you play unbelievable.

"The difference is just so little and can be so big.”

Verdasco said the reason he continued to watch the 2009 loss was because he needed to understand what occurred.

Head to head, Verdasco has only won three of 18 matches against Nadal. (Verdasco’s other two wins against the world No. 5 came in Madrid and Miami.)

“I mean, to learn,” Verdasco said in regard to why he continued to watch the match. “To see how I played, how I took the chances, how I didn't. With 4-4, love-30, I’m supposed to be more aggressive, go forward more, try to play deeper. If I miss, I miss long. But [not] like in the net. It was five hours, so it was many things during that match. But we played unbelievable, both of us.

"It was super intense during the five hours. But I just see my matches. I like to watch tennis, not only myself. Yesterday I was watching [a] little bit of [Grigor] Dimitrov with [Paolo] Lorenzi. I was watching also Roger [Federer]. I love tennis and I've been watching tennis since I'm a kid. Now because I'm here in this position, I will not change that. So I think from every match you can learn something.”