كتب : Omar AbdelAziz
Germany striker Kevin Kuranyi opened the score line after ten minutes, Gerald Asamoah doubled the lead on 34 minutes and Brazilian midfielder Lincoln completed the rout in the 71st minute.
Schalke kept their place in charge of the Bundesliga table on 59 points, while Mainz remain second from bottom on 30 points, on level with 16th-placed Arminia Bielefeld who also crashed to a 4-2 home defeat to Eintracht Frankfurt.
Schalke chasers VFB Stuttgart came from behind to earn a 2-1 victory over Hannover 96.
Steve Cherundolo's strike for Hannover cancelled out Roberto Hilbert's second-minute opener before an own goal by defender Dariusz Zuraw in the 74th minute sealed the victory for Stuttgart.
Bundesliga top scorer Theofanis Gekas took his tally to 17 goals when he fired home after one minute to give Bochum an early lead against Hertha Berlin, but the latter made a sizzling fight back in the second-half to win 3-1.
A Chhunly Pagenburg strike proved enough to give Nurnberg a 1-0 win against Alemania Aachen, as Nurnberg jumped to 5th place on 44 points.