Since being appointed to the Irish set-up in 2002, Saracens coach Ford has been instrumental in the squad's rise to assuming the role of Grand Slam contenders.
"Mike Ford must get a big mention for delivering a defensive performance like that," said O'Sullivan, who departs with Ford for New Zealand on May 24, as part of the large British and Irish Lions coaching panel.
"Everybody's really believing in what we are doing now and to go back two or three years we would not have won that game. We would have leaked a try or two at some juncture and the game would have slipped away from us.
He added: "There were periods of the game when England were very dominant. They played great rugby and were stretching the ball from touchline to touchline and very aggressively.
"We had to defend, not just heroically. We needed to throw our bodies on the line and know when and how to throw our bodies on the line. We showed great discipline and that is why they had very few kicks at goal."
In all, Ireland made 106 tackles yesterday to England's 45, as they gallantly defended their try line. Something which will please Ford too, is the fact that the men in green have shipped 43 points and four tries so far in the 2005 Championship.
Compared with 63 points and seven touchdowns conceded, at this stage last year.
Mike FordBorn: November 18, 1965
Playing Career: Played Rugby League for 20 years with Wigan, Leigh, Castleford, South Queensland and Oldham, and also won 10 caps for Great Britain. He was part of the RL British Lions tour to Papua New Guinea and New Zealand in 1988.
Ford retired from the 13-man as player-coach of Oldham in 2001.
Coaching career: Appointed Ireland Defensive Co-Ordinator in January 2002. Appointed Saracens Defence & Skills Coach in September 2004. Works with the Zurich Premiership club when not in training camp with Ireland, or on international duty.
Ford was also appointed to the 2005 British and Irish Lions coaching panel for the New Zealand tour, last year.