Stoke City edged out Tottenham Hotspur 7-6 on penalties after the game finished 0-0 at the end of extra-time and Newcastle United beat Nottingham Forest, like Spurs four-times winners of the trophy, 4-3 in a thriller after extra time.
Arsenal had to come from behind to beat League Two Shrewsbury Town 3-1 at Emirates Stadium while Bolton Wanderers won 2-0 at fellow Premier League side Aston Villa.
"The first half was a tremendous performance by us, our movement off the ball and possession were very good," Ferguson told Sky Sports. "Leeds kept trying and trying (but) we just wanted to make sure we went through."
Asked about Owen he added: "His ratio of goals [to games] is unbelievable. His second goal in particular was fantastic... he's not getting the (number of) games he deserves."
Arsenal's terrible start to the season looked like continuing when they fell behind to James Collins's 16th-minute header for Shrewsbury but Kieran Gibbs levelled in the 33rd.
Alex Oxlade-Chamberlain, 18, put last season's runners-up ahead before the hour and Yossi Benayoun also got his first Arsenal goal to ease the pressure on manager Arsene Wenger.
"It was a bit nervy because we played against a good side," Wenger said on the club's website. "I said before the game the lower divisions have improved in the last five years and you could see that."
Tottenham's campaign ended when 18-year-old substitute Massimo Luongo's penalty was saved by Stoke's Thomas Sorensen while Newcastle progressed when Fabricio Coloccini grabbed a last-gasp winner at Championship team Forest.
