With the Mets and Phillies scoreless in the bottom of the fifth inning, Hessman launched the first pitch of the frame against Cole Hamels deep to left field.
Phillies left fielder Raul Ibanez went back on the fly ball but ran out of room up against the wall, and the ball hit off the top of the wall before rolling to the left-field grass while Hessman rounded second base.
Ibanez and center fielder Shane Victorino instantly asked for a fan-interference call from the umpires, but home-plate umpire Ed Rapuano signaled a home run for Hessman, who completed his trot and put the first run on the board.
Phillies manager Charlie Manuel came out to argue the call, and after a short conference, the umpires decided to review the ruling.
Upon watching replays of the hit, the umpires -- led by crew chief Tom Hallion -- determined there was fan interference on the play and placed Hessman at third base, where they believed he would've ended up had there been no interference.
Hamels struck out the next two batters, and after intentionally walking Ruben Tejada, he fielded a comebacker from Mets starting pitcher R.A. Dickey to end the inning, preventing Hessman from scoring and preserving the scoreless tie.
The Mets took the lead on a Carlos Beltran double to left-center field off Hamels with two outs in the sixth inning.
Dickey lost his bid for the first no-hitter in Mets history with one out in the sixth inning, when Hamels singled to right field.
Kyle Maistri is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.