Manchester City saw an unlikely hero emerge from their galaxy of superstars to make a potentially defining contribution in their pursuit of an unprecedented fourth successive Premier League title.
Pep Guardiola rightly acted with caution when he removed keeper Ederson, with City leading 1-0, after he suffered a nasty blow to the head in a heavy collision at the foot of his post with Tottenham defender Cristian Romero.
Ederson, who had a problem with his eye, did not look happy with the decision - taken upon advice from the club doctor - but his manager was perfectly justified, not just acting in the best interests of the Brazilian keeper but also because he has complete trust in his replacement Stefan Ortega.
And in a 21-minute cameo of the highest quality, Ortega - who has performed with distinction every time he has deputised for Ederson this season - may well have rubber-stamped City’s sixth title in seven seasons.
When the final whistle sounded and the club stood one win away from being champions again, Guardiola headed straight for Ortega and greeted the German with a kiss on the cheek for his crucial contribution. It was richly deserved.
Guardiola did not hold back with the praise as he said: "Ortega is a world-class goalkeeper. An exceptional, exceptional goalkeeper. Ederson did not have concussion, he had a problem with his eye. He could not see properly so the doctor said I should change."
Spurs made a complete mockery of the cynics who suggested they may ease off because any sort of positive result could potentially give rivals Arsenal their first Premier League title in 20 years.
Ange Postecoglou’s fifth-placed side were fully committed in chasing a goal of their own as they went after a place in the Champions League and it was not for any lack of effort as they came so close to upsetting City’s traditional title charge. They were left disappointed in the end as defeat confirmed Aston Villa's fourth-placed finish and they will now join European football's top table.
Ortega's impact was instant, denying Spurs substitute Dejan Kulusevski with a good save and then the same player shortly afterwards as City almost paid the price for a performance that was not one of their best.
The biggest moment came in the closing minutes, with City clinging on to a one-goal lead, when Son Heung-min collected the ball and raced clear with only Ortega to beat. It was the sort of opportunity the South Korean has taken with aplomb so many times in his Spurs career.
Yet Ortega stayed strong, stayed on his feet, waited for Son to make his move before stretching out his right leg to make the save that may well seal another Premier League triumph.
Guardiola, who clearly feared the worst, threw himself on his back dramatically in his technical area in an animated display of agony and then sheer relief, while Manchester City captain Kyle Walker likened Ortega, and the save, to the keeper's fellow countryman, Bayern Munich icon Manuel Neuer. Praise indeed.
It was Spurs’ last stand as Erling Haaland added his second of the night from the penalty spot in added time for his 38th goal of the season. If City beat West Ham United at Etihad Stadium on Sunday, the formalities will be complete.
Haaland may grab some headlines as his remarkable goalscoring feats continue, despite this season not being quite as prolific as his first, but Ortega was top of the bill. The keeper's involvement was short and sweet but spectacular and probably decisive.
He was needed because this was not City at their peak but they are so well schooled in being in this position that a muscle memory kicks in to ensure they get the job done at the season’s pressure points.
Since City lost at Aston Villa in December, they are unbeaten in 22 Premier League games, winning 18 and drawing four in the sort of unstoppable surge that threatens to break Arsenal’s hearts in the same way they have also broken Liverpool’s on the final day of the season in previous years.
Experience means their players appear impervious to the natural pressures and when you possess players of the quality of Haaland and Kevin de Bruyne, allied to their telepathic relationship, there always remains the capacity to make the difference.
And so it proved in the 51st minute for the vital opener, De Bruyne providing the 112th assist of his City career to lay a goal on a plate for Haaland.
It still needed the outstanding intervention of Ortega, who will long be remembered by his grateful manager and colleagues as they raced to him to show their appreciation before the celebrations started in front of the joyous travelling fans.
City are now in the position they have occupied so often and one from which they rarely slip.
It would be a shock to see them stumble now – and so much of the credit for that must go to Stefan Ortega.