Primero stuck to a small lead group on the way home for a fifth overall finish, the best by any Asian in the 171-km route from Kelang the small but progressive town of Tampin.
American Sean Sullivan of Team Barloworld won the stage with a time of 3 hours, 20 minutes and 15 seconds. But the leaderboard was hardly shaken as Freddy Gonzales of Colombia Selle-Italia remained on top.
The six-man lead group survived three mountain passes and parried the main groups attack in the long stretch to the finish.
Although Primeros heroics did not put him in the top 10 of the Asian classification, he towed Pagcor for a best Asian team finish in the stage.
Pagcor remained at fourth place but trimmed the gap from leaders Japan, Iran and China.
The rest of the seven-man team, led by team captain Victor Espiritu, arrived one minute and 29 seconds off the stage winner.
Ryan Tanguilig and Espiritu retained their 8th and 9th rankings, respectively, in the Asian individual race. Tanguilig is behind by 7 min and 49 seconds off Asian Individual leader Ghader Mizbani of Iran. Espiritu is three seconds behind Tanguilig.