Rory McIlroy of Northern Ireland hits out of a sand trap on the fourth hole during the third round of the WGC-HSBC Champions golf tournament in Shanghai November 2, 2013.[Photo/Agencies]

Rory McIlroy and his tennis-playing girlfriend Caroline Wozniacki started the New Year with a bang on Wednesday by announcing their engagement on Twitter.

"Happy New Year everyone! I have a feeling it's going to be a great year!! My first victory of 2014 #shesaidyes!!," golfer McIlroy, who rang in the New Year with Wozniacki in Sydney, wrote.

The two former world number ones in their respective sports have been dating for more than two years and erroneous reports their relationship was over last year was proposed by some as an explanation for McIlroy's drop in form.

Northern Irishman McIlroy, 24, had to wait until December to claim his first title of the season when he dramatically edged Adam Scott on the final hole to win the Australian Open.

Wozniacki, 23, pulled out of this week's Brisbane International with an injured right shoulder but is confident she will be able to play in this week's Sydney International in preparation for the January 13-26 Australian Open.

"Happy New Year everyone! Rory and I started 2014 with a bang! ... I said YES!!!!" Wozniacki tweeted above a picture of her hand sporting an engagement ring.