Fernando Alonso has boldly claimed McLaren have the "best car" in Mexico after an eye-catching performance in Q1.
Alonso was running as high as P5 in the first qualifying session, just two tenths off the pace and setting the fastest middle sector of everyone before ducking out of Q2 because of the impending grid penalties due to engine changes.
"It was good fun in Q1 to show the potential of the car," Alonso said in the paddock.
"Yesterday was a nice surprise, how strong we were – the car felt great in the corners, in the high speed section, and today we proved it again in qualifying.
"Being two-tenths off P1 in qualifying, that shows probably for the first time in the last three years we had the best car out there."
Alonso unsurprisingly gave all the credit to McLaren for the chassis improvement, as opposed to Honda providing anything useful with the power unit.
"Today we have the previous engine," he added. "Yesterday we used the new engine but saved it for Brazil and Abu Dhabi.
"So all the improvements are thanks to the aero and a bit to the suspension parts we've brought over the past races.
"It's been a while since we set a pink sector. It's probably the best weekend of the whole season."