Federer won the Qatar Open in 2005 and 2006
Roger Federer and Rafael Nadal remain on course for an early showdown in 2010 after both came through their second-round matches in Qatar on Wednesday.
World number one Federer needed a little over an hour to beat Russia's Evgeny Korolev 6-2 6-4.
Nadal was on court for nine minutes longer in a 6-2 6-2 win over Italian Potito Starace.
"I've been playing well lately. Today's victory underlines that I'm in very good form," said the Spaniard.
"Potito has always been a tough opponent for me."
The pair, now through to the quarter-finals, are seeded to meet for the 21st time in Sunday's final.
Third seed Nikolay Davydenko is among those hoping to prevent that happening, and the Russian brushed aside Marco Chiudinelli 6-3 6-4 to reach the last eight.
Davydenko will face seventh seed Ivo Karlovic in the quarter-finals.
Federer, who won the Qatar Open in 2006 and 2006, meets Ernests Gulbis, while Nadal will play qualifier Steve Darcis of Belgium.
Darcis knocked out Younes El Aynaoui, the 38-year-old who on Tuesday became the oldest man in 15 years to win an ATP match.