Defending champion Ashley Wagner seized a comfortable lead in the ladies\' short programme at the 2013 US figure skating championships. Wagner, a heavy favorite to retain the title she won last year, amassed 67.57 points, putting herself in position to become the first woman to win back-to-back US titles since Michelle Kwan won her last two national crowns in 2004 and 2005. Agnes Zawadszki was in second, more than two points back on 65.31 and Mirai Nagasu was third on 64.39. Wagner enjoyed a strong Grand Prix season that included taking silver at the Grand Prix Final in Sochi, Russia, behind Mao Asada of Japan in December. But she fell hard in her free skate in Sochi and came into nationals still battling an injury to her right knee, but there was no sign of a problem during her clean short programme to music from the \"Red Violin\" soundtrack. Marissa Castelli and Simon Shnapir took the lead in pairs competition with a spirited short programme to \"Stray Cat Strut\". A powerful throw triple Salchow highlighted their routine, which earned 62.27 points and gave them a nine-point lead over the rest of the field. \"This is a high-intensity programme,\" Shnapir said. \"It\'s a fun programme, so I think coupled with a little bit of nervousness, we really got going right from the get-go. We had a couple of bobbles here and there, but overall we were happy with what we put out there.\" The pairs competition was thrown wide open with the withdrawal of defending champions Caydee Denney and John Coughlin, because of Coughlin\'s hip surgery. None of the top three teams from last year\'s championships were entered. The two other pairs on the podium last year have ended their partnerships. Felicia Zhang and Nate Bartholomay were second after the short programme on 53.19 points. Alexa Scimeca and Chris Knierim were lying third on 52.79. Competition continues on Friday with the ice dance short programme and men\'s short programme. Pairs, ladies and ice dance medals will be decided with the free skate on Saturday, while men\'s competition concludes on Sunday. The men\'s field took a blow when 2010 Olympic gold medallist Evan Lysacek confirmed last week he wouldn\'t compete as he continues to recover from surgery to repair a hernia. From AFP