The former Derry City and Shamrock Rovers hero scored the second goal with an assured finish from a Marco Fortune pass to give Neil Lennon his first win as Celtic manager after Georgios Samaras had scored a first half penalty.
McCourt's ability is in absolutely no doubt but after two years at Celtic under three different managers he has still to complete a competitive 90 minutes.
At 26 the player is frustrated by the lack of first team chances which are further limited by the SPL rule that clubs must list three U21 players in their match day squads. Ian Holloway is an admirer of McCourt and wants to add to Blackpool's 16-man squad for their first ever Premier League campaign.
Celtic paid Derry £100,000 for McCourt two years ago and are believed to be looking for £750,000 from Blackpool despite the player being in the final year of his contract.
McCourt played in centre midfield in the win over Seattle and was involved in everything that Celtic created, finding time on the ball and space to link with team-mates.
Less that 48 hours on from their defeat by Manchester United in Toronto Lennon changed his entire team in order to assess his full squad.
Samaras scored from the penalty spot for the second game running and is believed to be interesting several Spanish clubs who were impressed by his World Cup performances for Greece.
The former Manchester City striker is also in the final year of his contract with Celtic believed to be ready to do business if a £2m offer is put in front of them.