The last time Halep and Watson faced off, the Romanian survived a three set duel in the first round of last year's US Open.
Halep got up an early break and cruised to a first set win. After going down a break in the second set, Halep won three straight games and never gave up her lead, going on to a comfortable 6-2, 6-4 victory.
By The Numbers
Halep won 75% of her first serve points, while Watson made good on just 49%. And though her break point percentage wasn't great, Halep managed to secure five of them out of 13 chances compared to two out of six for Watson. Halep has now won eight of her past nine matches dating back to her runner-up showing in Madrid.
"I feel very good. I'm 100% here," Halep said. "That's why I stopped in Rome, to be ready to play here. I have had two good matches here. The second set was a little bit difficult today and I was a little nervous. But I served well and that was good.
"There is a little pressure, but I just want to stay focused for every match because here every match is very tough. It's a tough tournament, and I have to play my best. I expect every match to be difficult, so I cannot say that I'm thinking about the finals or anything like that."
"Today was tough," Watson said. "Simona played very well, as I knew she would. I don't think I was on my best game. I made a lot more unforced errors than I usually do, and I thought my first serve percentage wasn't very high. But at the end of the day, she made hardly any unforced errors and she made me make my unforced errors, so you have to give her credit for that."