Kipkemboi Kiprono completed a Kenyan 1-2-3, with Wales' Dewi Griffiths fourth in a personal best time of 1:01.31.
Edith Chelimo also set a course record as she won the women's race, with Dorcas Kimeli and Beatrice Mutai completing another Kenyan clean sweep.
Melissa Nichols and Richie Powell won the wheelchair races.
The event drew a record entry of 25,000, made up of elite, club and charity runners.
"It was pretty fast from the start," said 26-year-old Griffiths, a three-time Welsh marathon champion
"The race organisers asked for a fast pace so it was just about how long I could stick with it really and go as hard and fast as I can.
"I knew I was in great shape, I've PB-ed over the past couple of weeks and it's another PB today.
"The crowds were great, the support was great. It was a great event again."
Jenny Nesbitt took the Welsh national title - run alongside the main event - finishing in a personal best time of 01:13:23.