It was the third time on as many circuits that he has been involved in a collision.
Vettel was issued a penalty for unsafe driving in Azerbaijan a year ago after hitting Hamilton twice behind the safety vehicle, angered by what he saw as risky maneuvers from the British driver.
Despite his start to the campaign, Hamilton remains confident that he and his Mercedes team can made the necessary improvements to allow his to retain his championship - but conceded that his championship rivals have made significant strides in the recent past.
Hamilton, on pole position past year when the race was held in the much hotter month of June, is still chasing his first win of a campaign that is well on the way to becoming a classic.
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Daniel Ricciardo won a thrilling race for Red Bull, Lance Stroll took an excellent podium and Sebastian Vettel intentionally bashed his Ferrari into Lewis Hamilton's Mercedes after believing that the Briton brake-tested him under the safety auto.
The out-of-contract Perth driver is now weighing up his options with Ferrari, Red Bull and Mercedes for next season and victory on Sunday will further enhance his growing reputation.
"Now we have Red Bull close to their best and Ferrari at their best, if we are able to pull through and deliver as we have in previous years it would be the biggest achievement this team would have accomplished".
Mercedes team boss Toto Wolff, for one, is relishing a three-way battle with Red Bull and Ferrari for the constructors' title, while the teams' drivers fight for individual honours. The vehicle has been great but in the last race it wasn't performing the way it normally does. 2018 has not seen the Spaniard hold his weight up to this point. With 51 laps winding around the historic and picturesque city center, it is a demanding circuit that will be another exciting round of the 2018 Formula 1 championship.
The first day of the FIA Formula 2 races started in Baku April 28.