That left Alonso with a big lead going into the August break, and Horner admits that Red Bull and its drivers urgently need to make in-roads into this if they're to be in with a chance of the title of the end of the season.
"We need to beat him more," Horner said simply. "Obviously the main objective is to get both drivers right up there with Fernando.
But with Ferrari currently a one-man show with Alonso, things are looking much better for Red Bull as a whole with a big lead over McLaren in the constructors' battle.
"We're unlucky not to be sitting here with four race wins after the disappointment of Valencia, but to have won in Monaco, Silverstone and Bahrain we've got a more than 50-point lead in the constructors' championship," said Horner. "The first half of the year has been an interesting half for us. The way that the regulations evolved over the winter and the way that we've managed to deal with that I think we've got a better understanding of the car."
That need to develop understanding seems to have held Vettel back more than his team mate, suggested Horner.
"In qualifying, Sebastian hasn't been as comfortable with the car on the Saturday as he has on the Sunday - or certainly as comfortable as he was last year when his one-lap performances were quite remarkable," he said.
"But I think he's getting there, I think he's getting to a point where he's happier with the car; it's getting more to his liking and hopefully both he and Mark can put a strong run of qualifying performances together in the remaining races."
Unfortunately Webber will have to overcome a five place starting grid penalty for Sunday's race, after needing another out-of-sequence gearbox change following the final race before the August break at the Hungaroring in July.