Swansea 'squandered the chance' to win South Wales derby, Williams acknowledges
Swansea City were on course to beat Cardiff City through Liam Cullen's early goal, until Callum Robinson struck later on for the Bluebirds.
Luke Williams feels Swansea City "squandered the chance" to take all three points in the South Wales derby, as they were held to a 1-1 draw by Cardiff City.
The Swans took a 10th-minute lead through academy graduate Liam Cullen, who volleyed home from close range after Ethan Horvath parried Ronald's initial effort.
However, they were pegged back 11 minutes from time when substitutes Ollie Tanner and Callum Robinson combined, with the latter ensuring a share of the spoils.
Tempers flared late on at the Swansea.com Stadium, with Cardiff boss Erol Bulut sent off for refusing to hand the ball back and his involvement in confrontations with Jay Fulton and Kyle Naughton.
Swansea had won five of the six previous league meetings between the sides on home soil, and Williams was left frustrated after his side failed to convert their general control of proceedings into a second goal.
"I think it was a very cagey game," he told Sky Sports. "The first half, we were probably the better team and deserved our lead at half-time, but the second half was a lot more even.
"I think if we'd scored the second goal, we would have taken the game away from them, but at 1-0, there is always that jeopardy.
"We squandered the chance today. It is frustrating as it is a huge game, and we know what it means. But we didn't get that second goal and then, as a coach, you probably fear the worst and really, we got what we deserved.
"On the whole, we defended well, but we didn't for one action, and the ball ended up in the back of the net. We switched off for one moment and got punished."
Meanwhile, Cardiff finally got off the mark in a season that began with back-to-back defeats against Sunderland and Burnley, in which they conceded seven goals without reply.
"We knew it would be a passionate game," Bluebirds assistant Omer Riza said. "We've worked really hard today and have ended up with a draw and, overall, we are happy.
"Going 1-0 down early meant today was always difficult, but we stuck to our guns. In the second half, we had more intent, pressed better, and we always felt our subs would be important today.
On red card, he added: "There was a challenge that frustrated Erol, he was pulled onto the pitch by one of their players and the red card is a bit harsh."