The double Olympic champion was a straightforward winner at the European Team Championships at Gateshead last week but faced a much stiffer challenge at Alexander Stadium, with the world's two fastest men over the distance - Ethiopian pair Yenew Alamirew and Hagos Gebrhiwet - on the start line.
But was more than equal to it, seeing off both rivals in a final lap dash for the finish.
Gebrhiwet was first to drop off the pace, leaving Farah and Alamirew going head-to-head. Farah had more than enough as he came home in 13 minutes, 14.24 seconds to Alamirew's 13mins 14.71secs.
With the World Championships in Moscow coming up in August, Farah's status as the man to beat is assured.
Farah, whose last lap was timed at 53.40secs, told BBC2: "The young guys wanted to beat me, I'm the man to beat.
"Today I had to dig deep. The guys were working as a team, but you've got to hold your form and make sure you have something left.
"I am training hard, it's all about the World Championships."