Another retirement wasn't far behind, and it was a car with a similar but not identical livery: Mark Webber was told that his KERS had failed, but almost before he could digest this news there was a far more terminal issue with the alternator of the Red Bull that forced him to park his car, this time at turn 14. That put Alonso up into a third position, and suddenly his boasts about being able to outpoint Vettel in Austin didn't seem like such wild flights of fancy after all.
For Alonso to really make in-roads into Vettel in the championship, he urgently needed Hamilton to take the lead from the German. But Hamilton wasn't able to make that long-awaited move on Vettel for the lead, his tyres looking past their best after all their hard work catching back up to the Red Bull in the early laps, and on lap 21 Hamilton was in to change to the harder prime tyres for the second half of the race. Alonso was in at the same time, and Vettel needed to react next time by: McLaren and Red Bull both put in astoundingly fast pit stops, but Alonso's was noticeably slower.
Vettel resumed in the lead ahead of Raikkonen who had yet to stop, which was frustrating for Hamilton who was running immediately behind the Lotus for a couple of laps before being able to pass for position. Massa was in fourth place pending his own visit to the pit lane, while behind him Alonso's slow pit stop had left him exposed to attack from Jenson Button for fifth place, which the Briton accomplished on lap 24 despite his far older set of tyres. It was proving to be a fine recovery run from Button, who was having to work hard in the first half of the race after dropping to 16th place on the first lap following his poor grid position following technical problems in qualifying on Saturday.
Raikkonen pitted on lap 25, but a slow stop because of a clutch issue meant that any hopes he had of coming back out in front of Fernando Alonso were long gone. Instead, the Finn had his hands full trying - and failing - to hold off the Toro Rosso of Daniel Ricciardo for fifth place.
As the race reached the halfway point, backmarkers had cost Hamilton some time and he was now once again over two seconds off the back of race leader Vettel. Button was maintaining third place ahead of Alonso and Ricciardo, who finally pitted on lap 32 and fell to 13th as a result, while Massa had earlier pitted on lap 27 and was left wrestling with Raikkonen over what had become fifth place.
Raikkonen won that lengthy duel and fifth place become fourth when Button finally came in for his long-deferred pit stop on lap 36, and a welcome switch to the grippier but less durable option tyres, the reverse strategy to the majority of the cars in Texas. Disappointingly, Button failed to make it back out ahead of Felipe Massa as planned despite the Ferrari having been held up in traffic and he had to make do with seventh behind Romain Grosjean; even so, the McLaren pit wall were reassuring Button that he was much faster that anyone else around him at this point of the race, and he proved it with a relatively easy slice past the Lotus on lap 39. Sensing the danger from behind, Massa responded by taking advantage of Raikkonen running wide in turn 10 at lap 40 to pass for position - although the two came perilously close to a collision as Raikkonen sought to recover back onto the track.
All the while, Vettel continued to lead the race: but Hamilton was creeping closer and closer, and finally on lap 41 Hamilton had his first serious look down the inside of turn 11 to state his intentions. Vettel fended him off and tried to pull away again, but the McLaren had enough to stay with him and next lap through the DRS advantage was simply too overwhelming. Despite trying to move over to thwart Hamilton, there was nothing Vettel could do as the McLaren sailed past. Furious, he was quickly on the Red Bull team radio to vent about HRT's Narain Karthikeyan, whose sluggish presence up the road had limited Vettel's ability to defend.
In the meantime, Hamilton tried pulling away out of the DRS activation distance as fast as he could, thwarting any ideas Vettel might have had about counterattacking. That was good news in terms of the championship for Alonso, who was still calmly lapping in third place.
Hamilton's team mate Jenson Button was also enjoying himself now, finally winning a hard-fought, no quarter given duel with Kimi Raikkonen for fifth place to put him on course to chase down Felipe Massa up the road in fourth. After an initial surge, a KERS issue forced Button to ease off and settle for the positions he'd already gained. The rest of the top ten with half a dozen laps remaining to the chequered flag was comprised of Grosjean, Hulkenberg and the two Williams cars of Bruno Senna and Pastor Maldonado, which were once again demonstrating mighty straight line speed in race trim.
Less happy with how things were going were the Saubers of Sergio Perez (11th) and Kamui Kobayashi (14th) and the Mercedes of Nico Rosberg (13th) and Michael Schumacher (16th), after the multiple former world champion had needed to abandon his one-stop strategy for a second costly tyre change on lap 40. Toro Rosso would also have surely been disappointed with Daniel Ricciardo running out of the points in 12th place after that fine first half performance from 18th on the grid.