Ghana midfielder Amankwah Forson registered an assist to help Championship side Norwich City reach the second round of the EFL Cup in an entertaining encounter against Stevenage at Carrow Road.
Canaries academy product Abu Kamara and Cuba winger Hernandez struck for City before the break, only for Boro to go in level through equalisers from new signings Charlie Goode and Louis Appere.
Borja Sainz and Hernandez then struck to put new manager Johannes Hoff Thorup on course for the first win of his reign since taking over at Norwich.
Stevenage scored a third when Brad Hills diverted Lewis Freestone's cross into his own net with two minutes remaining, but the League One side were unable to find a fourth to take the tie to penalties.
Kamara's 26th-minute opener came after fine work by Sainz and full debutant Amankwah Forson.
But City's frailties at the back would have worried Thorup, who watched Goode find an abundance of space to head in Harvey White's cross.
Another White delivery confused Norwich's defence a minute into first-half added time, Appere applying the finishing touch in a crowded penalty area.
Stevenage, whose starting side featured seven changes from their 1-0 win over Shrewsbury Town, struggled to create clear chances during the second half.
An eye-catching City attacking sequence three minutes after the interval allowed Sainz to fire them ahead again before Hernandez collected Forson's pass and showed clever footwork to tee himself up and lash in.
Amankwah arrived at Norwich City from Austrian Bundesliga giants Red Bull Salzburg on a permanent deal last week and has already made two appearance for the club.
