Theatre claims Peterborough Chase Riverside Theatre stayed on best to claim a narrow victory for Nicky Henderson in the Betfred Peterborough Chase at Huntingdon. Champion Court turned the extended two and a half-mile event into a gruelling test with a bold front-running display and several of his rivals were forced into jumping mistakes along the way. Riverside Theatre first came under pressure with just less than a circuit to travel but Barry Geraghty never gave up on the well-backed 9/4 favourite and stayed close enough to mount a renewed challenge late on. Ghizao, Captain Chris and Module were all fought off by the gallant runner-up Champion Court after holding every chance turning in, but Riverside Theatre jumped the last fence well and had enough momentum to claim the spoils by half a length. Geraghty told Racing UK: "Had a lot of ground to make up but I knew he was staying on. Two and a half miles around here is possibly sharp enough for him but he's stayed on well. "He wasn't travelling but I was happy enough where I was and they went a good gallop. Going to the ditch it didn't look brilliant but down the back I knew we were well in it." Henderson added: "Barry said he knew he'd won at the second last. He does finish his races well as we've seen in before in races such as the Ryanair Chase. "He probably wants further these days, it was sharp enough round here and they took him off his feet early. "Last year in the middle part of races not a lot was happening but he's finished well. He's not lazy, it's just possibly a lack of pace now. "We've done an awful lot of different things with him - his wind, his ulcers. He wears a duvet in the parade ring. Whether they're making any difference or not I'm not sure. "Maybe some cheekpieces might make a different at some stage. "We ran him in the King George last year first time out in the hope he's best fresh, but I'm never going to rule anything out. "It might not strike as the most obvious thing to do at the minute but he's still in it and the option is there. Jimmy (Nesbit, owner) has the told me has the day off so we'll see!" The winner was cut to 25/1 from 33s by Sky Bet for the King George at Kempton, while the third home Captain Chris, runner-up to Long Run in the Boxing Day feature 12 months ago, is 12/1 from 16/1.