If you want to watch a particular event it might be worth checking up whether it's being shown on Sky. If so, you can get yourself a NOW TV box, including a one month pass to all Sky Sports channels (excluding a few 'pay-per-view' events, such as major boxing matches) for £34.99:
http://www.nowtv.com/box#ib-section-section-5
You're not committed to any contract. If you don't go any further with your sports subscription your box will still function to access catch-up TV services, Youtube, etc free of charge. If you want to access Sky Sports after that you can pay £6.99 for a single day, £10.99 for a week or £31.99 for a full month:
http://tinyurl.com/zetrkkt