Jovanovski charged down the slot and swatted at the airborne rebound of Vernon Fiddler's shot. The puck went past goaltender Chris Mason and into the net. The goal was allowed after a lengthy video review.
"We've been preaching about going hard to the net," Jovanovski said. "I just barged to the net and it hit my shaft and went in."
It was Jovanovski's second of the season; both have been game-winners.
Asked it he was nervous about the long video review, Jovanovski said: "Any time they take over a minute, you get a little antsy."
The Coyotes won for the fourth time in six games and for the first time this season at Jobing.com Arena. St. Louis has lost three in a row after starting the season with back-to-back wins over Detroit in Stockholm.
After a scoreless first period, the Blues took the lead 3:22 into the second during a delayed penalty.
The Blues were all over the Coyotes with the extra attacker until David Backes scored on a straightaway, 45-foot wrist shot that sailed through a pile of bodies and into the top corner past Ilya Bryzgalov.
Phoenix finally ended its scoreless streak at 172 minutes and 59 seconds when captain Shane Doan got his first of the season at 10:36. Doan was just off the left post and wound up in perfect position when Adrian Aucoin's errant shot from the right point hit the boards and came right to him for a quick flip past Mason.
It was the Coyotes' first goal since Matt Lombardi scored 2:37 into the third period at Buffalo last Thursday.
Bryzgalov, who has been arguably the NHL's best goaltender during the first two weeks of the season, got caught napping when the Blues went ahead 2-1 on Paul Kariya's goal at 12:19. Keith Yandle controlled the puck behind his own net and stepped out to the right. Kariya snuck in, swatted the puck off Yandle's stick and into the net at 12:19, stunning the crowd and Bryzgalov.
But the Coyotes began to pick up their play and tied the game at 8:27 of the third when Scottie Upshall converted Lombardi's cross-ice feed on a 2-on-1 break. Phoenix controlled play in the final period, outshooting St. Louis 11-3 -- only several fine saves by Mason earned the Blues a point.
--John Kreiser, NHL.com
Material from team online and broadcast media was used in this report
1 - 0 STL
1 - 1 Tie
2 - 1 STL
2 - 2 Tie