ST. PETERSBURG — Josef Newgarden did enough Sunday to defend one of his titles. Just not the one that mattered the most.Newgarden used a gutsy restart sequence to win the Firestone Grand Prix of St. Petersburg but couldn’t make up enough points to catch Scott Dixon, who clinched a sixth IndyCar championship by finishing third in the series' season finale.“It’s definitely bittersweet,” Newgarden said.The sweet part was obvious. Needing a victory and some help to have a shot at a third career IndyCar title (and second in a row), Newgarden did all that he could do.His No. 1 Team Penske Chevrolet was up front for most of the day as other contenders on powerhouse teams dropped out. First it was teammate Will Power, who started from the pole here for the ninth time.But his No. 12 Chevrolet had mechanical problems downshifting, then hit an outside wall on Lap 37 to finish last in the 24-car field.“Just lost it,” said Power, a two-time Grand Prix winner.So did the driver who took the lead from Power, Alexander Rossi. The 2016 Indianapolis 500 champion led 61 of the first 69 laps before getting loose in the marbles and crashing in a rough day for Andretti Autosport.Newgarden, however, avoided the six cautions that covered 26 of the 100 laps.“We outlasted everybody,” Newgarden said.The 29-year-old Tennessee native made his triumphant charge on a restart on Lap 80. He started the run in third and bolted inside Belleair’s Colton Herta in Turn 1. Then he steered outside Alex Palou on the next corner to take the lead for good.By cruising to a 4.1-second win over runnerup Pato O’Ward, Newgarden became the third driver in a row to repeat as Grand Prix winner (Juan Pablo Montoya won in 2015-16, and St. Petersburg resident Sebastien Bourdais won in 2017-18). His second triumph here came in unusual circumstances; instead of serving as IndyCar’s opener in March, the early days of the coronavirus pandemic forced the race to move to the end of the season.As Newgarden cruised to his 18th career victory, he rarely got any information from his team about Dixon’s position. It wouldn’t have mattered, anyway.“We just did what we could,” Newgarden said, “and hoped for the best.”That’s where the bitter part comes in for one of IndyCar’s biggest American stars. He simply entered the weekend too far behind Dixon.Dixon won four of the first eight races to build up a massive points lead on Newgarden and the rest of the field. The 40-year-old New Zealand native needed only to finish ninth or better to finish as a wire-to-wire champion.That didn’t seem like much of a problem for Dixon. Like Newgarden, Dixon stayed near the front for much of the day and — as he always seems to do — avoided any major issues. His No. 9 Chip Ganassi Racing Honda stayed on a similar pit strategy as Newgarden to reduce his odds of getting caught in an unlucky caution.Even with a big points lead, Dixon refused to race conservatively. When Newgarden darted to the lead on the restart, Dixon made a few moves behind him to keep his adversary from pulling too far ahead.The result was Dixon’s sixth podium in 16 career races here — a strong performance at one of the few tracks where he has never won.“It feels really cool to finally celebrate something here,” Dixon said, “I have a lot of memories here. Some of them are not so great.”This one, however, was special. A championship that capped off a wild, dominant season and put him one behind the legendary A.J. Foyt for the most ever.“Six is good,” Dixon said after slipping on a black mask that read INDYCAR CHAMPIONS. “Seven sounds better.” That quest starts on these downtown streets in 133 days when the Grand Prix returns to its usual March spot as IndyCar’s opener.