Perth - The United States pairing of Coco Vandeweghe and Jack Sock edged closer to the final of the mixed teams Hopman Cup with a 3-0 win over Spain in Perth on Tuesday.
Both teams had won their first round robin matches and the victory means the USA only needs to beat Australia on Thursday to be certain of advancing to Saturday's final.
The United States has already won the tournament a record six times.
Vandeweghe continued her encouraging start to the year with a 6-2, 6-4 win over Lara Arruabarrena in the women's singles, before Sock secured the tie for the Americans with a three-set victory over Feliciano Lopez.
The Americans made it a clean sweep in the dead mixed doubles rubber.
Vandeweghe, ranked 36th, opened her year with a win over Lucie Hradecka and raised her game against the 65th-ranked Arruabarrena.
Her serving was impressive with eight aces and the 25-year-old believed it was a more polished performance than in the opening match.
"I think I did different things better today, I felt a little bit better moving," she said.
"I thought my serve was all over the place, but it was good when it counted.
"I was a bit on and off with it and hopefully I can tighten it up a bit.
"There are still things to work on and things to improve."
The 23rd-ranked Sock was made to work overtime by the cagey Lopez, who is just five places lower at 28.
The American blew an early break in the first set and dropped it 6-3 to fall behind, but steadied to win in three sets in stifling heat which appeared to trouble both players.
Sock gained a crucial break in the fourth game of the final set, after a lengthy game on the Lopez serve.
The Spaniard had a break point in the seventh game, but couldn't convert and it took Sock 98 minutes to win 6-3, 2-6, 6-3.
"There are definitely things to improve on," Sock said.
"I didn't think I served as well in the first match, but I dictated points on my forehand."
The dead mixed doubles was played in the Fast Four format and the Americans prevailed in a third set tiebreak, 4-3 (5-3), 3-4 (2-5), 4-3 (5/2).
Result from the tennis mixed teams Hopman Cup at the Perth Arena on Tuesday:
United States bt Spain 3-0
Women's singles: Coco Vandeweghe (USA) bt Lara Arruabarrena (ESP) 6-2, 6-4
Men's singles: Jack Sock (USA) bt Feliciano Lopez (ESP) 3-6, 6-2, 6-3
Mixed doubles: Vandeweghe/Sock (USA) bt Arruabarrena/Lopez (ESP) 4-3 (5/3), 3-4 (2/5), 4-3 (5/2) (fast four)