While with the "Blues", Livingstone went on to only make one substitute appearance, playing in a 3–0 defeat to Manchester United at Old Trafford on 17 April; he replaced Neil Shipperley in the 55th minute of the game.
In September 1993, he was signed by Port Vale manager John Rudge on a one-month loan; he played five Second Division games before returning to London.
He was an instant hit at Blundell Park and his performances earned him respect amongst the "Mariners" fans, he formed notable impressive strike partnerships with Clive Mendonca, Jack Lester and Lee Nogan.
With Alan Buckley returning as manager, the "Mariners" won immediate promotion in 1997–98 after beating Northampton Town 1–0 in the Second Division play-off final at Wembley.
[5] Grimsby also found success at Wembley in the Football League Trophy final after beating AFC Bournemouth 2–1 after extra time; Livingstone was a 55th-minute substitute for Daryl Clare.
Livingstone played 34 games in the 1999–2000 campaign, as Grimsby finished two places above the relegation zone; he scored just two goals, both coming against Stockport County in the FA Cup.
New manager Lennie Lawrence was appointed for the 2000–01 campaign, and Livingstone continued to be a key player, finishing as the club's top-scorer with seven goals in 36 games.
On 17 August 2002, he collided badly with Derby County defender Danny Higginbotham and was knocked unconscious; this left Livingstone with a head injury that would see him out of action for a couple of months.
[7] His old target man status returned briefly, as he helped Grimsby edge a thrilling 6–5 win over Burnley in an impressive performance alongside fellow striker Steve Kabba.