Sam Querrey fought from a set down to defeat Laslo Djere and John Isner won a fifth-set tiebreaker over Dusan LaJovic to give the United States a 2-0 lead over Serbia in the first round of the Davis Cup World Group on Friday.
Querrey had 20 aces in a 6-7 (4), 6-2, 7-5, 6-4 win in the opening singles, and Isner followed with 24 aces in his 6-4, 6-7 (6), 6-3, 3-6, 7-6 (4) victory.
Host Serbia is playing without Novak Djokovic and Viktor Troicki. It won the last two ties against the U.S., including in 2010 when it went on to win the title.
The U.S. can clinch the victory in the series in Saturday's doubles, when Ryan Harrison and Steve Johnson face Nikola Milojevic and Miljan Zekic.
Defending champion France got off to a slow start at home against the Netherlands as Adrian Mannarino was upset by Thiemo de Bakker, a player more than 300 places below him in the rankings, 7-6 (4), 6-3, 6-3. Richard Gasquet leveled the score by defeating Robin Haase 6-4, 7-6 (3), 3-6, 7-5.
Last year's runner-up Belgium opened a 2-0 lead over visiting Hungary as Ruben Bemelmans defeated Marton Fucsovics 6-4, 4-6, 7-6 (5), 6-3 and David Goffin beat Attila Balazs 6-4, 6-4, 6-0.
Spain, without Rafael Nadal, moved ahead of Great Britain when Albert Ramos-Vinolas defeated Liam Broady 6-3, 6-4, 7-6 (6), but 114th-ranked Norrie Cameron evened the series by rallying from two sets down to upset Roberto Bautista-Agut 4-6, 3-6, 6-3, 6-2, 6-2. Spain is playing its first tie at home since 2013.
Croatia, runner-up to Argentina two years ago, opened a 1-0 lead over Canada at home with Borna Coric's 3-6, 6-2, 6-3, 6-2 victory over Vasek Pospisil, but Denis Shapovalov tied the series by defeating Viktor Galovic 6-4, 6-4, 6-2.
Germany led host Australia after Alexander Zverev defeated Alex de Minaur 7-5, 4-6, 4-6, 6-3, 7-6 (4), but Nick Kyrgios leveled the score with a comfortable 6-4, 6-4, 6-4 win over Jan-Lennard Struff.
Fabio Fognini defeated Taro Daniel 6-4, 3-6, 4-6, 6-3, 6-2 to give Italy the lead over Japan, but the hosts evened the series with Yuichi Sugita beating Andreas Seppi 4-6, 6-2, 6-4, 4-6, 7-6 (1).
Switzerland, without Roger Federer and Stan Wawrinka, was losing 2-0 at Kazakhstan. Dmitry Popko defeated Henri Laaksonen 6-2, 7-6 (7), 3-6, 7-5 and Mikhail Kukushkin beat Adrian Bodmer 3-6, 6-3, 6-2, 6-3.
