By Alan Baldwin

ISTANBUL (Reuters) - Title rivals Michael Schumacher and Fernando Alonso dominated final free practice for the Turkish Grand Prix on Saturday with the Ferrari ace coming out on top.

The German, just 10 points behind Renault's Formula One world champion with five races remaining in a finely balanced battle for the crown, lapped an overcast Istanbul Park circuit in one minute 27.203 seconds.

The seven times world champion completed 12 laps and saved his best to last, producing his quickest effort as the clock ticked away the last seconds of the final session before qualifying.

Alonso had struggled with graining tyres on Friday but his optimism that the team would find a solution overnight appeared well-founded as he ended the session second quickest but 0.721 seconds slower than Schumacher after 16 laps.

The 25-year-old Spaniard is using the same engine he had in Hungary, even though he failed to finish that wet race, because Renault are planning to introduce an upgraded version at the next race in Monza.

Alonso's Italian team mate Giancarlo Fisichella also did his bit to raise Renault's hopes with third place on the timesheets ahead of Poland's Robert Kubica in a BMW Sauber.

Schumacher's Brazilian team mate Felipe Massa, who has a crucial role in the constructors' championship with Ferrari only seven points behind Renault, was seventh.

McLaren's Kimi Raikkonen, last year's winner of the inaugural Turkish Grand Prix from pole position, was ninth quickest but looked ragged at times.

Jenson Button ended the session with the sixth best time for Honda after celebrating the first grand prix win of his career in Hungary two weeks ago.