The French striker scored the Gunners' third goal in the 4-1 rout of the Royals and believes they can take advantage when Tottenham face Chelsea and Manchester City
Arsene Wenger's team thrashed Reading 4-1 on Saturday to draw within two points of Chelsea and four points of Tottenham, the latter of whom have played one game more.
Giroud was on the scoresheet at the Emirates Stadium and believes Arsenal can capitalise when Spurs face the likes of Chelsea and Manchester City in the coming weeks.
"We want to be ambitious and keep our focus," he told reporters. "The championship is until May 19. There's eight games to play and a lot of points to play for.
"I trust in our qualities so I really think we can make fourth and maybe even third place if we continue to play like this.
"We want to dictate the games. We are confident. We are used to finishing the championship well. And this season we will do the same.
"Spurs have to play against Manchester City and Chelsea so they are hard games. But every game is difficult, we can see that Chelsea lost at Southampton. We have to keep focus, concentrated and strong.
"We are scoring lots of goals. We need to be more concentrated when we are defending because we need more clean sheets because we dominate games. But we are playing well."
Arsenal went in front through Gervinho against Nigel Adkins' team and the under-fire forward went on to play a part in two more goals as the hosts established a comfortable lead.
Wenger admitted after the match that the Ivorian is not always the most ruthless finisher but was pleased to see him take some of the pressure off himself with a strong display.
"Gervinho is not a clinical finisher but when he is completely relaxed he is quite good," he said. "He rushes his finishing because when he arrives in front of the goal, he wants to, you know, 'Get rid of that.'
"My worry was that he played in front of a negative atmosphere here so you always think you must persist to give him the confidence but you risk putting him further down if it doesn't work.
"The big problem the last two years has been the Africa Cup of Nations. Each time he came back it took him a while to recover. But we work with him in front of goal of course.
"In training, he finishes well – better than when he arrived. It will get better and better. His finishing is linked with his psychology. Players are up and down.
"But Gervinho wants to do well. He loves football. He is a hard worker. Physically, you cannot fault his effort. Even when he had a bad period, he always tried very hard."