The champions had survived a huge scare in the drawn game when Gary Sice slotted a late free two weeks ago but Tuam did not offer the same resistance this time around at Tuam Stadium yesterday.
Both goals came in the first-half as Corofin held a 2-3 to 0-6 interval lead, but the deficit was down to two points eight minutes after the break.
Corofin goalkeeper Tom Healy then superbly saved a Cormac McWalter penalty as Stephen Rochford’s side maintained their push for a three-in-a-row of county titles for the first time.
The Stars looked impressive early on as Conor Rhatigan and Gary O’Donnell hit points but then Lundy netted after eight minutes before Jason Leonard tacked on a point. Conor Doherty and Gavan Connell hit back to tie the game, but again the home side were hit with a sucker-punch.
A wonderful move ended with a hand-pass from Ronan Steede to Martin Farragher, and he hammered home Corofin’s second goal in the 19th minute.
Farragher and Gary Sice followed up to put Corofin 2-3 to 0-4 ahead and in control.
But two late points from Connell and Jamie Murphy left Tuam three behind at half-time. Murphy hit the first score on the resumption but Corofin refused to buckle.
McWalter’s penalty was brilliantly saved by Healy, and Corofin advanced to play Cortoon Shamrocks in the final four.
Salthill/Knocknacarra beat Killannin, 0-12 to 1-6, at Pearse Stadium after surviving a late scare when Johnny Heaney netted a 55th-minute penalty for Killannin. The former All-Ireland champions dominated the first-half but only led 0-6 to 0-4 at half-time.
But when Heaney found the net an upset looked on the cards. Yet Salthill/Knocknacarra held their nerve, and backed by the inspired introduction of young forward Rob Finnerty, they advanced to the last four.