Miami, Mar 28 (IANS): Swiss tennis legend Roger Federer topped Argentina's Juan Martin del Potro 6-3, 6-4 to claim a spot in the fourth round of the Miami Open here on Monday.

Though the Swiss great and Delpo have faced each other 20 times in the past 10 years, this was their first match in Miami and members of the South Florida Argentine community packed the stands at Crandon Park Tennis Center in Key Biscayne to cheer on their countryman, reports Efe.

Federer took 15 of those contests, but Del Potro came out ahead three of the last five times they met.

On Monday, however, Federer was clearly in command and the world No.6 won the first set in 38 minutes.

Del Porto, ranked 32nd, appeared to lose pace and power after bandaging his wrist during the second set, yet he was able to prolong the contest by saving a break point in the seventh game before Federer's decisive forehand winner in the 10th.

Next up for Federer, winner of the Australian Open and Indian Wells, will be Spaniard Roberto Bautista, who beat US player Sam Querrey 3-6, 6-2, 6-3 earlier on Monday.

Bautista battled back to defeat Querrey 3-6, 6-2, 6-3 in the third round. Querrey, ranked 22nd in the world, stole the headlines three weeks ago when he upset Rafael Nadal in the final of the Acapulco Open.

He started strong Monday amid the South Florida heat at Crandon Park Tennis Center in Key Biscayne and broke Bautista's serve twice on the way to winning the first set.

World No.18 Bautista answered with two service breaks of his own in the second set to win 6-2. He went on to take the third set 6-3, unfazed by the Miami crowd's obvious preference for the American.

The Spaniard, who improved his record against Querrey to 3-0, must now prepare to face Switzerland's Roger Federer in the fourth round.