Gio was called for at half-time of Mexico's Group B match against Gabon at Coventry and responded with a match-winning display, scoring in the 63rd and 92nd minutes as his side ran out 2-0 winners.
It means a point against Switzerland on Wednesday will be enough for Mexico to progress to the quarter-finals.
Great Britain also just need a point from their final match against Uruguay in Cardiff on Wednesday to progress after a tough 3-1 win against UAE at Wembley.
Steven Caulker started again and played the full 90 minutes but Danny Rose was an unused substitute this time as Team GB scored late, also through substitutes, as Scott Sinclair and Daniel Sturridge saw them home to a 3-1 victory.
Earlier, UAE's Rashed Eisa levelled Ryan Giggs' 16th-minute opener.
Our final Spurs interest saw Sandro play for 64 minutes as Brazil toppled Belarus 3-1 at Old Trafford to secure their place in the last eight. They complete Group C against New Zealand on Wednesday.