Reigning European Formula 3 champion Felix Rosenqvist claimed a race win on his debut in the Indy Lights series in St Petersburg.
Rosenqvist split the wins with early championship leader Felix Serralles in the season opener.
The Swede had qualified well in second, but couldn't make the most of his front-row grid position for his first ever rolling start in Saturday's opening race, dropping down to sixth.
Kaiser started from pole, but a bold getaway from Zach Veach propelled him from third to first, ahead of Kaiser and a storming Serralles, who moved up from seventh.
Veach opened up a comfortable lead of 1.7 seconds, but on lap 17 an electrical fault vaulted the three-time Lights winner to the back.
That promoted Serralles to first, and he secured the win ahead of Scott Hargrove and Kyle Kaiser.
Debutants Rosenqvist and Dean Stoneman finished seventh and eighth respectively.
While Rosenqvist lost out in the first race, the two-time Macau Grand Prix winner proved he had learned from that when he won the second race with a controlled lights-to-flag victory.
An early yellow flag period thanks to a clumsy overtake attempt by Shelby Blackstock, and lapped traffic that failed to heed blue flags looked to challenge Rosenqvist's dominance, cutting his 3.4s lead down to 1.8s.
But the Belardi Auto Racing driver rebuilt that advantage, crossing the line 4.3s ahead of Kaiser and Veach.
With a third and a second, Kaiser sits second in the championship behind Serralles, with Rosenqvist third.
Racing with Andretti Autosport, Stoneman had a better day to finish sixth for race two.
RACE 1 RESULTS - 30 LAPS:
|2||Scott Hargrove||Team Pelfrey||5.5336s|
|3||Kyle Kaiser||Juncos Racing||6.1320s|
|4||Santiago Urrutia||Schmidt Peterson Motorsports||7.8009s|
|5||R.C. Enerson||Schmidt Peterson Motorsports||8.4345s|
|6||Andre Negrao||Schmidt Peterson Motorsports||12.1840s|
|7||Felix Rosenqvist||Belardi Auto Racing||12.8449s|
|8||Dean Stoneman||Andretti Autosport||13.5796s|
|9||Juan Piedrahita||Team Pelfrey||15.7225s|
|11||Zachary Claman||Juncos Racing||46.5642s|
|13||Scott Anderson||Schmidt Peterson Motorsports||47.7760s|
|14||Shelby Blackstock||Andretti Autosport||48.1225s|
|15||Dalton Kellett||Andretti Autosport||1 Lap|
|16||Zach Veach||Belardi Auto Racing||3 Laps|
RACE 2 RESULTS - 45 LAPS:
|1||Felix Rosenqvist||Belardi Auto Racing||51m45.8621s|
|2||Kyle Kaiser||Juncos Racing||4.3675s|
|3||Zach Veach||Belardi Auto Racing||7.4736s|
|5||Andre Negrao||Schmidt Peterson Motorsports||13.4341s|
|6||Dean Stoneman||Andretti Autosport||14.2443s|
|8||Juan Piedrahita||Team Pelfrey||19.8197s|
|9||Scott Anderson||Schmidt Peterson Motorsports||1m07.6326s|
|10||Dalton Kellett||Andretti Autosport||1m08.9158s|
|11||Shelby Blackstock||Andretti Autosport||1 Lap|
|12||R.C. Enerson||Schmidt Peterson Motorsports||1 Lap|
|13||Santiago Urrutia||Schmidt Peterson Motorsports||1 Lap|
|14||Scott Hargrove||Team Pelfrey||1 Lap|
|16||Zachary Claman||Juncos Racing||Spun off|
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