The U.S. Open can be viewed on the ESPN channels and live streamed on WatchESPN. So everything together", said Halep, who was coming off consecutive runs to the final at hard-court tuneup tournaments at Cincinnati and Montreal.
The American crushed 24 winners to go with 22 unforced errors on her way to a win in 76 minutes.
SA qualifier Lloyd Harris was beaten in his first-round match by Gilles Simon 6-2 6-2 6-3.
It was the sixth time in the Open era that the number one seed has lost in the first round of a Grand Slam tournament and the first at the US Open. However, Day 1 witnessed 33-degree Celsius heat instead of rain. I like the city", said Kanepi.
Kanepi, a former Top 15 player from Estonia, on the other hand, was completely in control of the match, employing her huge serve and massive groundstrokes to dictate play from the start.
Halep recovered and it appeared a comeback was on when she broke Kanepi to love to level the second set at 4-4.
On this day, though, Kanepi took charge of baseline exchanges, compiling a 26-9 edge in winners, 14 on her favored forehand side alone.
"She has been playing really well in United States lately, so I thought I just have to be aggressive and try to stay calm", said Kanepi.
Garbine Muguruza did not come close to defending her Wimbledon title, falling in the second round, but the 12th seed thrashed Zhang Shuai 6-3 6-0.
Eventually, Halep got going a bit, taking advantage of Kanepi's mistakes to break back twice and get to 4-all in that set.
"I didn't play great, but she played really well. Because normally, they cheer for the underdog", Kanepi said with a smile.
But Kanepi ended a 14-stroke exchange with a cross-court forehand volley victor to break right back, then served out the victory.