Will Power has ended the opening practice session of the INDYCAR Grand Prix fastest at the Indianapolis Motor Speedway road course, only just ahead of four-time champion Scott Dixon.
The Penske racer produced his benchmark in the final second of the session, which had been dominated by Dixon in the Honda-powered Ganassi car during the final few minutes.
Barber race winner Josef Newgarden ended the session P3 for Penske, after a competitive start to the weekend.
Newgarden was one of the first drivers to complete a timed lap in the opening practice session, which was initially interrupted by a red flag delay due to debris on the back straight.
Once the debris had been cleared a frenetic session ensued, with the benchmark at the top quickly tumbling as more and more drivers began pushing to the limit and beyond.
Reigning champion and 2016 INDYCAR Grand Prix race winner Simon Pagenaud was fourth fastest for Penske, despite running off track on several occasions throughout the session.
Spencer Pigot was P5 after a somewhat surprisingly competitive session, which saw him even briefly rise to the top of the order during the early stages.
Graham Rahal was one of four Honda-powered drivers to end the session within the top ten in sixth, only just ahead of the Penske of Juan Pablo Montoya.
The 1999 champion, who is competing in his first IndyCar race since the Grand Prix of Sonoma last September, was only just ahead of former Formula 1 racer Max Chilton.
The Briton enjoyed a competitive start to the 45-minute session but soon fell down the order when the Penske racers began producing their lap times.
Carlos Munoz and James Hinchcliffe rounded out the top ten, ahead of reining Indianapolis 500 champion Alexander Rossi who could only manage P11.
Veterans Helio Castroneves and Tony Kanaan were unable to break into the top ten, with the Chip Ganassi racer in particular enduring a scruffy session, locking-up into Turn 1 and running wide at Turn 12 on the same lap.
