Andretti Autosport driver Rossi set the best time of 1m10.091s on the 2.439-mile road course at Indianapolis Motor Speedway to pip Team Penske's Newgarden - whose participation had been in doubt after losing consciousness following a crash at Iowa last weekend - by just 0.020s.
Colton Herta made it two Andretti Autosport runners in the top three, 0.058s behind in third, while Newgarden's team-mate Scott McLaughlin was fourth ahead of lead Chip Ganassi Racing driver Alex Palou.
Defending champion Palou, who is at the centre of a legal struggle with his own team after McLaren Racing announced that it had signed the Spaniard for an undisclosed programme in 2023, had gone quickest with around half an hour of the 90-minute session left to run on the hard compound Firestones.
Then Rinus VeeKay, who won on this course in May 2021, overhauled him on the alternate compound to slot his Ed Carpenter Racing entry into top spot.
Rossi and rookie team-mate Devlin DeFrancesco then moved into first and second with their second laps on the softer red tyres, but the pair were soon separated from each other by Rahal Letterman Lanigan drivers Jack Harvey and Rookie of the Year points leader Christian Lundgaard.
Herta then moved up to second before Newgarden, who was cleared to practice on the condition he would be re-evaluated afterwards, claimed second in the #2 Team Penske-Chevrolet in an impressive return to the cockpit after spending Sunday night under observation in hospital.
The third Team Penske driver, second in points Will Power, didn’t find the necessary speed while his reds were at their best and ended up only 18th fastest. He did, however, evoke a “nice save”comment from his strategist Ron Ruzewski after gathering up an alarming, smoky oversteer moment at Turn 8 while on the harder compound rubber.
Less successful in terms of honing their handling was Pato O’Ward, who took three adventures into grass and dirt in his Arrow McLaren SP-Chevrolet to finish up 20th fastest.
Romain Grosjean also appeared to have a very loose car, and languished adrift of his Andretti team-mates down in 21st at the scene of his first IndyCar pole last year.
Qualifying begins at 1pm local time today.
IndyCar Indy GP Practice Results:
| Cla | Driver | Team | Laps | Time | Gap | Mph |
|---|---|---|---|---|---|---|
| 1 |  Alexander Rossi | Andretti Autosport | 31 | 1'10.0919 | 125.270 | |
| 2 | Josef Newgarden | Team Penske | 27 | 1'10.1121 | 0.0202 | 125.234 |
| 3 | Colton Herta | Andretti Autosport | 25 | 1'10.1507 | 0.0588 | 125.165 |
| 4 |  Scott McLaughlin | Team Penske | 32 | 1'10.2065 | 0.1146 | 125.065 |
| 5 |  Alex Palou | Chip Ganassi Racing | 29 | 1'10.2093 | 0.1174 | 125.060 |
| 6 | Graham Rahal | Rahal Letterman Lanigan Racing | 29 | 1'10.2948 | 0.2029 | 124.908 |
| 7 |  Felix Rosenqvist | Arrow McLaren SP | 25 | 1'10.2948 | 0.2029 | 124.908 |
| 8 |  Christian Lundgaard | Rahal Letterman Lanigan Racing | 29 | 1'10.3237 | 0.2318 | 124.857 |
| 9 |  Helio Castroneves | Meyer Shank Racing | 25 | 1'10.3694 | 0.2775 | 124.776 |
| 10 | Conor Daly | Ed Carpenter Racing | 29 | 1'10.4016 | 0.3097 | 124.719 |
| 11 | Marcus Ericsson | Chip Ganassi Racing | 27 | 1'10.4739 | 0.3820 | 124.591 |
| 12 |  Callum Ilott | Juncos Hollinger Racing | 32 | 1'10.5234 | 0.4315 | 124.503 |
| 13 | David Malukas | Dale Coyne Racing | 30 | 1'10.5350 | 0.4431 | 124.483 |
| 14 | Jack Harvey | Rahal Letterman Lanigan Racing | 30 | 1'10.5927 | 0.5008 | 124.381 |
| 15 | Scott Dixon | Chip Ganassi Racing | 31 | 1'10.5991 | 0.5072 | 124.370 |
| 16 |  Simon Pagenaud | Meyer Shank Racing | 27 | 1'10.6038 | 0.5119 | 124.362 |
| 17 |  Devlin DeFrancesco | Andretti Autosport | 29 | 1'10.6040 | 0.5121 | 124.361 |
| 18 |  Will Power | Team Penske | 34 | 1'10.6196 | 0.5277 | 124.334 |
| 19 |  Rinus van Kalmthout | Ed Carpenter Racing | 30 | 1'10.6478 | 0.5559 | 124.284 |
| 20 |  Patricio O'Ward | Arrow McLaren SP | 26 | 1'10.7272 | 0.6353 | 124.145 |
| 21 | Romain Grosjean | Andretti Autosport | 30 | 1'10.7344 | 0.6425 | 124.132 |
| 22 | Kyle Kirkwood | A.J. Foyt Enterprises | 29 | 1'11.1466 | 1.0547 | 123.413 |
| 23 |  Takuma Sato | Dale Coyne Racing | 28 | 1'11.2690 | 1.1771 | 123.201 |
| 24 | Jimmie Johnson | Chip Ganassi Racing | 39 | 1'11.6786 | 1.5867 | 122.497 |
| 25 | Dalton Kellett | A.J. Foyt Enterprises | 20 | 1'12.4978 | 2.4059 | 121.113 |
| View full results | ||||||
