Quique Sanchez Flores was crestfallen but he cannot have been surprised. For the second time in five days his team had lost 2-1, conceding a late winner to a bigger club who they had outplayed. Last Monday, it was Tottenham Hotspur; on Saturday, Manchester City. And this time the winning goal was scored by someone the Watford manager knows well.
Sanchez Flores managed Sergio Aguero at Atletico Madrid, pairing the then 21-year-old up front with Diego Forlan and winning the 2010 Europa League. He still rates Aguero as the best player he has ever managed, along with David Silva, whom he coached at Valencia.
"I managed a lot of good players," he reflected. "But Silva and Aguero were a little bit different."
Aguero was not fully fit on Saturday, still recovering from a series of injuries which have ruined his season. At Arsenal and Leicester City recently, he was hauled off after an hour for Wilfried Bony. At Vicarage Road, Aguero was struggling to run in behind, missing that burst of pace.
A blunted Aguero means a blunted City - and they were outplayed for the first 80 minutes by Watford, 1-0 down before Yaya Toure's instinctive volley. But with six minutes left, Aguero, even on one leg, summoned enough power with his header to win City the game.
That is what the Argentine can do, even when operating nowhere near his best. If he can stay fit for the rest of the season then City will surely win the title. Sanchez Flores has thought all season that City would do it. On Saturday, his former player showed why.
"Aguero was at a high level, then he was injured for a short period," Sanchez Flores said. "It was enough to have some doubts, maybe. When you are injured, you lose your rhythm. But these kind of players have good physique, they recuperate their shape. Aguero is a completely different player. He is one of the best players in the world."
City manager Manuel Pellegrini spoke afterwards with the relief of a man whose team had just been sprung out of jail. They are now just three points behind leaders Arsenal, rather than six. It felt like a turning point in their season - and in Aguero's. Pellegrini was happy to embrace it as one.
"He has improved a lot in his whole performance, if you compare with his last game (at Leicester)," Pellegrini said. "We know he needs three or four games to return to his top performance. For him, the goal was important. Hopefully, he can go on. He is very important to our team, more than just one player."
Of course, City cannot hope to be bailed out by their big names in the last 10 minutes of every away game.
Bacary Sagna warned: "We have to be more careful because that won't happen every time. You have to take the game and create more chances."
As City returned to Manchester to prepare for their Capital One Cup semi-final first leg against Everton, Watford were reminding themselves how far they have come. Even after two painful defeats they were still in ninth place, more than halfway to safety and looking upwards.
Sanchez Flores added: "We are positive. We have 29 points and are always competitive."