Celtic need Rangers to stumble if they are to lift the SPL trophy in neil Lennons debut season as a manager. Celtic manager Neil Lennon is looking for Dundee United to "compete" against Rangers in tomorrow night's SPL game at Ibrox. The Hoops lost their advantage in the SPL title race when they lost to Inverness on Wednesday night. However, goals from Scott Brown and Kris Commons against Kilmarnock at Rugby Park yesterday saw them bounce back to be on the shoulder's of Rangers, who beat Hearts 4-0 at Ibrox on Saturday after beating Motherwell 5-0 at Fir Park the previous week. Celtic's goal difference advantage has now been cut to three and Lennon is looking for United to do him a favour against Rangers, 24 hours before he and his team travel to Tynecastle to face Hearts. Lennon said: "We have two games to go and anything can happen. What we are looking for is somebody to compete and give Rangers a game. There has not been much evidence of that in their previous two games. Even if we had drawn the game against Inverness on Wednesday night, I'm not sure goal difference would have made a difference, looking at the two games that Rangers have had. Dundee United have something to play for now (a European place). The results went for them at the weekend and they are looking for a result on Tuesday and we will be looking for a result on Wednesday. I didn't see the team Hearts put out, we were training at the time but listen, every team has their own agenda. I'm not going to cast aspersions at other clubs. I didn't see the (Rangers) game yesterday so I'm not going to sit here and criticise anyone's performance." Lennon acknowledged the importance of his captain Brown scoring with a close-range header in first-half injury time, after Gary Hooper and Commons both had the ball in the Killie net only to be flagged for offside. Lennon said: "We had two goals disallowed, I'm not sure why. I'm getting conflicting stories, I was told one was for a handball and then I was told both were offside. I will need to look at that. I thought we would score in the game, it was just a matter of when, but it was a great time to score. Scott is the captain and he came up trumps again." Lennon claimed that pound-for-pound there has not been a better signing this season than Commons, who arrived at Parkhead from Derby in January. The Scotland midfielder's drive from 25 yards in the 68th minute took his overall total for the season to 28, 13 of them for Celtic. The Celtic manager said: "I wouldn't have thought (there has been a better buy), not for £300,000. Mind you, Emilio Izaguirre at half a million/£600,000, has been a fantastic bit of business as was Beram Kayal, at 1.2 million euros. So we have been lucky in that respect, the players we have brought in this season have been magnificent. Kris is coming to the peak of his career. You almost get disappointed when he lashes a couple over the bar, he's that good. You can look at four or five of his goals for goal of the season. He has been tremendous, he has a tremendous work rate and he is always likely to pop up with a goal." Kilmarnock caretaker manager Kenny Shiels admitted Brown's goal to open the scoring was the turning point in the game. He said: "Until Celtic scored it was an even game. It was nip and tuck, I don't think anyone can disagree with that. We stretched Celtic and they stretched us. It was a bad time to concede and it had a psychological effect on their players and our players, one more adverse than the other. I tried to lift the spirits for the second half and we worked hard to get back into it. But the second half was a bit of a non-event and the game petered out after Commons' strike."