Reigning IndyCar Series champion Scott Dixon became the first driver to win for the second time in 2009, taking the chequered flag in the ABC Supply/AJ Foyt 225 at the Milwaukee Mile after long-time leader - and 2008 race winner - Ryan Briscoe was momentarily caught up in traffic.
By winning, Dixon took over the points lead for the first time since the end of the 2008 season, having clawed his way back from a disappointing start to his title defence.
It was Briscoe who dominated the race, however, leading 154 laps after passing early pacesetter Tony Kanaan on lap 26, but the Australian got caught up in lapped traffic on the tight Milwaukee circuit and, with Tomas Scheckter briefly taking his attention, Dixon seized the opportunity, passing for the lead with 24 laps remaining.
"I was trying to get the flow of traffic the whole day," revealed the Kiwi, who won earlier this season on the 1.5-mile oval at Kansas Speedway, "I definitely think that, from the start, our car was better. We could run quick times when we needed to, and we were good in traffic.
"We had many runs on Briscoe, but he kind of blocked a lot. That was kind of frustrating early on, but he definitely got caught up there, with Scheckter trying to take him on the bottom, and I got a great run on the high side and it just lined up perfect."
Briscoe earned three bonus points for winning the pole and leading the most laps, and has led laps in four races this season, more than any other driver.
"It was a great race, but Scott was just a little bit better than me at the end there," the Penske man admitted, "I was struggling with a little bit of understeer and, whenever I'd get on the inside, I'd really lose my momentum.
"It was a great job by Scott though. He was there all day long and took the opportunity to pass me when I got slowed up.
Dixon now holds a four-point advantage over Briscoe and Target Chip Ganassi Racing team-mate Dario Franchitti in the championship race, but other contenders were not so lucky.
Kanaan, despite snatching the lead on the opening lap, was eventually classified 19th after his car suffered a fiery engine failure, the first time he has finished outside the top four in six races at Milwaukee.