15K in 1:07:40

I went for a tempo run on Tuesday and did 15K instead of the scheduled 14K. I really wanted to confirm whether I am still as fast as I was on April 10th what with the interruptions and incompleted 32Ks. I had a question.
And the results were good.
I did the 13K on 10th April in 58:xx at an average pace of 4:31 min/km and I did the 15K in 1:07:40 at an average pace of 4:31 min/km. That is only a second slower and whats also interesting is that I closed the last 5K in 22:28 for the 15K while for the 13K I closed in 22:38. So I am definitely stronger aerobically. I have also noted that in both cases, my best paces are sub 4min/Km though the 15K was more controlled. So I am learning to control my pace.
Public service is not exactly a flat field and I hope those 4m elevations do count for something at the end of the day.
Here are the splits.
Split    Time       
           
1    4:29.6        
2    4:26.5        
3    4:30.3        
4    4:30.2        
5    4:36.0        
6    4:36.7        
7    4:35.1        
8    4:31.3        
9    4:32.8        
10    4:24.3        
11    4:40.8        
12    4:27.5        
13    4:30.1        
14    4:33.1        
15    4:16.5    
I think next time I should aim to go sub 4:30 min/Km average pace.
Like I said earlier, today I want to do some intervals in preparation for Sundays 32K.