The 25-year-old 'A Girl Like Me' hitmaker did not provide any explanation for being late at the concert, reported Daily Mirror.
There were speculations that the singer was watching a basketball game where Chicago Bulls were taking on Miami Heat in the opening contest of the NBA Eastern Conference semi-finals.
A lot of her fans to took to Twitter to vent out their anger against her.
After facing criticism for her late arrival Rihanna tweeted, "Boston I will never forget this night! I truly have deeper love for you now! Thank you for making it extra special! Diamonds World Tour (sic).