The midfielder returned from injury and was influential at Hampden as Philippe Clement’s side set-up an Old Firm final next month.
Cyriel Dessers scored both of the goals, with the opener coming after just five minutes, and Diomande felt the early strike was important as Rangers took control of the tie.
Speaking to RangersTV at full-time, he said: “I am very happy, first because we are into a final and that was the most important thing, but I am also happy to get back with the squad and get some minutes. I am happy to see Cyriel score two goals and to see the team do what we can do best and that is playing how the manager wants us to play and winning.
“I think in the first 30 minutes we were controlling the game we pushed a lot, we were winning a lot of balls and creating a lot of chances, so it was good to get an early goal.
“We got our first goal and that was good, but we know how these games go, we want to kill the game as soon as possible. The second goal was just as important as the first one so we were pushing very hard to get the second goal and eventually we got it so that was good, and we were chasing for more and more.”
Diomande was in midfield alongside Todd Cantwell, who had two assists this afternoon, and John Lundstram and he says he is enjoying playing alongside them both.
He continued: “They are amazing players, and I am happy to play with them, I can just be myself when I am around them because I just want to play football and good football and they also understand the game, so we just play and try to make the team better and that is the most important.”
With five crucial league fixtures to come before the Scottish Cup final on May 25, Diomande says the squad must put that to the back of their minds and give everything they can to have a successful end to the season.
He added: “We have six important games to go, and this is a very good result. The players are happy, and we see that if we work hard and play our style, we can dominate so we are going to take it one game at a time now and we are just going to give everything we can.
“The final is the last game of the season but now we are thinking of the next game, which is St Mirren, so we are going to go for that first.
“We are just going to take one game at a time and give everything we can to be where we need to be, to make the fans happy, to achieve our goals and be successful.”