After his sublime spin and win at Indianapolis a fortnight ago, Dixon put on another fuel-saving masterclass to take victory – despite a nine-place grid penalty that meant he started 16th – by 22s from Pato O’Ward (Arrow McLaren) and David Malukas (Dale Coyne Racing).
They were the only cars on the lead lap. Dixon used a three-stop strategy, while most of his rivals stopped five times.
Newgarden’s quest to win all the oval races in a single season for the first time in IndyCar history failed when he hit the wall late on while duelling for second, having led the early stages for Team Penske.
Polesitter Scott McLaughlin (Penske) had to start the race from 10th after a nine-place grid penalty that half a dozen cars took for using a fifth engine. That allowed Newgarden to lead the 28-car field to green, ahead of Colton Herta (Andretti Autosport) and O’Ward.
The caution flag flew almost immediately as Benjamin Pedersen’s AJ Foyt Racing car was rear-ended by Ed Carpenter into Turn 1 and spun into the wall. Carpenter was given a 30s penalty.
The race restarted on lap 11 with Newgarden leading Herta, O’Ward and Malukas – who had rocketed up to fourth from sixth on the grid – and the other McLarens of Felix Rosenqvist and Alexander Rossi. Malukas went around the outside of O’Ward at Turn 1 to grab third, with Rosenqvist further demoting O’Ward.
Series dominator Alex Palou (Chip Ganassi Racing) was the best placed of the penalised starters, up from 14th to take ninth from Linus Lundqvist (Meyer Shank Racing) and running ahead of McLaughlin.
Malukas passed Herta for second and he lost momentum, so O’Ward, Rosenqvist and Rossi managed to jump past him too. Herta bailed into the pits, as did Palou – who opted for the alternate tyres, which were making their oval debut at this event.
Newgarden extended a 3.2s lead over Malukas before making his first stop, taking alternates, on lap 62. Will Power (Penske) and Scott Dixon (Ganassi) ran longest, making it to lap 65. Dixon rejoined on alternates.
Despite his pre-pitstop slump, Herta managed to undercut those ahead of him to regain second, 1.6s behind Newgarden. But O’Ward, on alternates, passed Herta for second on lap 70 and chased down Newgarden as Herta battled to keep Malukas and Rosenqvist behind him in third.
O’Ward pitted from second on lap 103, going back to primaries, while Newgarden went a lap later, and did likewise. O’Ward attacked Newgarden, who caught leaders Herta and Malukas who were running long on old rubber.
Dixon again ran longest and inherited the lead, as Power bailed out early on this stint. Dixon was able to pit under yellow on lap 125 when team-mate Takuma Sato crashed into the Turn 2 wall, just after Palou had passed Herta.
Marcus Ericsson (Ganassi) worked his way into the top eight but his car lost its left-rear wheel as he left the pits but it didn’t cost him many places as the caution came to his rescue.
Indy Road Course winner Dixon retained the lead, putting him back on the same strategy as everyone else, ahead of Newgarden, O’Ward, Rossi, McLaughlin and Malukas. The big losers at this point were Power, Herta, Palou and Rosenqvist – with the last three almost colliding as they dived for the pitlane as they made a late call to top-off on fuel.
At the restart on lap 135, just past the halfway point, O’Ward banged wheels over second with Newgarden entering Turn 3, which allowed Dixon to scamper clear.
Palou and Herta duelled hard over 10th – with the points leader keen to make progress with his nearest title rivals running 1-2.
O’Ward pitted from third on lap 166, triggering a sequence of stops by Newgarden, Rossi, McLaughlin and Malukas. O’Ward managed to undercut Newgarden to take a net second.
Dixon stayed out, leading Ericsson, Herta and Power as the strategies diverged again. Ericsson pitted on lap 178, with Herta also bailing on a long run a lap later. Power pitted on lap 189.
Dixon pitted for the final time on lap 195 with 65 laps remaining, promoting O’Ward to the lead from Newgarden, Rossi, McLaughlin, Malukas and Palou – but they would all have to stop again.
Dixon rejoined in 10th, 10s behind the leader, but in by far the best position strategy-wise.
Newgarden pitted for the final time with 52 laps to go, in an attempt to undercut back past O’Ward, but the McLarens of O’Ward and Rossi stayed out, leading Herta and Dixon.
As he was pushing to gain the advantage over O’Ward, Newgarden hit the wall at Turn 2 having got on the marbles in the wake of Devlin Defrancesco. It broke his suspension and ended his feint title hopes and his chance to sweep the series’ ovals.
The race stayed green, as Malukas and McLaughlin’s amazing fight almost ended in contact at Turn 4, with Malukas barging his way past and McLaughlin losing a spot to Palou.
O’Ward pitted with 47 laps to go, with Rossi doing likewise four laps later. Herta pitted from the lead with 40 to go, handing the top spot of Dixon – who had Power hounding him in a vain attempt to push him into busting his fuel number. Power pitted with 13 to go, dropping him to 10th.
Dixon had everything under control and cruised to victory by 22.2256s over O’Ward, Malukas, Rossi and McLaughlin.
Herta finished sixth, ahead of Palou, Rosenqvist, Power and Ericsson.
Palou leads Dixon by 74 points with two races remaining.
IndyCar St Louis race results
