A persistent, nagging cough bothering world number one Serena Williams since her Australian Open victory gave Argentina a chink of light in their one-sided Fed Cup tie against the United States on Sunday.

However, Argentine number one Paula Ormaechea’s 6-4 6-4 win over Coco Vanderweghe, standing in for Williams, was a minor setback on the Americans’ way to a 4-1 victory in the World Group II tie at Pilara outside Buenos Aires.

“Since last night, we’d seen that (Serena) wasn’t going to play much... I knew I would have revenge,” Ormaechea, beaten in two sets by Venus Williams on Saturday, told reporters.

Venus Williams dispatched Maria Irigoyen 6-1 6-4 as the record 17 times champions U.S. cruised towards a promotion playoff in April in their bid to regain World Group I status.

“It was a great atmosphere, we played well and I’m proud of the win,” said Venus Williams.

The Williams sisters had put their team 2-0 up on Saturday with wins over world number 121 Ormaechea and number 197 Irigoyen whose country were seeded and had a choice of court, opting for clay, despite the huge gap in world rankings favouring the Americans.

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