2009 125cc world champion Julian Simon has won the final race of the season, after exchanging the lead with team-mate Bradley Smith three times on the last lap at Valencia.

Smith suffered a scare when his bike stopped on the warm-up lap, but the double 2009 race winner got his Aspar Aprilia restarted just in time to take up third on the grid.

The interruption certainly didn't do the Englishman any harm as he rocketed off the line to take the holeshot at turn one, then pulled a 1.4sec lead over Simon by the end of the first lap!

Simon was initially hampered by attacks from Marc Marquez, but once able to escape he quickly closed down Smith's lead and was locked onto the Englishman's back wheel by lap 5 of 24.

The Aspar riders rode in formation into the distance, holding a seven second lead as the halfway point came and went.

Simon had snatched victory from Smith on the last lap of the two previous events, a thought that must have been weighing heavily on Smith's mind as the Spaniard sat patiently behind him for lap after lap.

On the other hand, Simon's two previous events on home asphalt had ended with the #60 crashing out at Jerez then celebrating one lap early in Catalunya.

This time it was Smith who made the mistake, running wide with four laps to go and gifting Simon the lead - but the #38 battled back to within striking distance as the last lap began.

The Englishman, desperate to beat Simon in their last race together for at least a season, made a lunge for the lead early in the lap, but Simon cut straight back inside on the exit. Smith then struck again under braking at the end of the back straight, only for Simon to nip back past through the twisty sections.

That set up a last turn showdown, with late-braking star Simon taking a defensive inside line, while Smith opted for a wide entry to try and blast past on the exit. It didn't work and Simon held on for his seventh win of the season and last in 125 before switching to Moto2 next year.