Murray books quarters spot

Miami - Reigning US Open champion and second seed Andy Murray blasted nine aces en route to a 7-6 (7/3), 6-3 victory over Bulgarian Grigor Dimitrov in the third round of the Miami Masters on Monday.

Murray, who won this event four years ago, needed one hour and 54 minutes to oust the 29th seeded Dimitrov.

Last year's runner-up to Novak Djokovic would have faced a tougher task had not the 21-year-old lost his composure when serving for the first set at 5-3.

Dimitrov double faulted three times to allow Murray to break back and the doughty Scot duly got the better in the tie-break.

It is the second time in as many tournaments that Dimitrov has cracked when serving for a set against a top-ranked player, serving up four double faults when he led world No 1 Djokovic 5-3 in the third round at Indian Wells.

Murray, who committed 22 unforced errors to Dimitrov's 38, will face Italian Andrea Seppi in the fourth round, the 16th seed having beaten experienced Brazilian Thomaz Bellucci 7-5, 4-6, 6-2.

Meanwhile, eighth-seeded Frenchman Richard Gasquet rolled over 28th-seeded Russian Mikhail Youzhny 6-3, 6-4 and 10th-seeded Spaniard Nicolas Almagro beat Belgian David Goffin 6-3, 6-4. Gasquet faces Almagro in the fourth round.

Also, sixth seed Jo-Wilfried Tsonga, of France, cruised past Finland's Jarkko Nieminen 6-3, 6-3.

Results on Tuesday from the eighth day of the $8.5 million WTA and ATP Masters Miami hardcourt tournament (x denotes seeding):

Men

Fourth round

David Ferrer (ESP x3) bt Kei Nishikori (JPN x13) 6-4, 6-2
Jurgen Melzer (AUT) bt Albert Ramos (ESP) 2-6, 6-3, 6-3
Richard Gasquet (FRA x8) bt Nicolas Almagro (ESP x10) 6-7 (3/7), 7-5, 7-6 (7/3)
Andy Murray (GBR x2) bt Andreas Seppi (ITA x16) 6-2, 6-4
Tomas Berdych (CZE x4) bt Sam Querrey (USA x17) 6-1, 6-1
Marin Cilic (CRO x9) bt Jo-Wilfried Tsonga (FRA x6) 7-5, 7-6 (7/4)
Gilles Simon (FRA x11) bt Janko Tipsarevic (SRB x7) 5-7, 6-2, 6-2
Tommy Haas (GER x15) bt Novak Djokovic (SRB x1) 6-2, 6-4

Women

Quarter-finals

Serena Williams (USA x1) bt Li Na (CHN x5) 6-3, 7-6 (7/5)
Agnieszka Radwanska (POL x4) bt Kirsten Flipkens (BEL x30) 4-6, 6-4, 6-2